Pagoda SL Group
W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: dseretakis on October 12, 2007, 15:17:33
-
Its been over one and a half years now that my 280 SL will not run. It started when I was driving home and the car just stalled and would not restart. I pushed it into the garage of my apartment building where it has sat eversince. I figured it was probably ignition related as there was fuel coming from the fuel line going to the intake manifold when I disconnected the line. I did not however measure the rate of flow. I proceeded then to replace the points, rotor, cap, condenser, wires, plugs and got the car to start, run poorly from anywhere from 15 secs to up to 2 minutes and then stall again. I gave up and left the car that way for 1.5 years. I figured that maybe the ignition coil was bad so I replaced it today. Again no change. It runs poorly for 30 secs to a couple of minutes while giving it a good amount of gas and then stalls. I'm at a loss. I don't wan't to just keep replacing parts. I'm starting to suspect the fuel system again. Any ideas? Thanks,
Dimitri
-
Hello Dimitri,
I remember you posting about a year and a half ago. Don't get discouraged, a little persistence will pay off!
If you have a fuel tank (flower pot) problem, often times adding fuel to raise the level in the tank will temporarily solve the running problem. If your fuel level is below one half, try adding at least 5 gallons of fuel.
Joe Alexander
Blacklick, Ohio
-
Hello,
I had a similar problem with regards to stalling recently, and it did turn out to be the fuel pump. My car stalled primarily at idle, but ran at speed. I would not have guessed at the fuel pump from the symptoms. There is a fuel line connection at the driver's side engine mount, which you can detach and check the flow. I know that other posts list how to measure it and the expected amount, but the flow rate is substantial. Replacement fuel pumps are indeed expensive, so I would suggest getting the prior post data and measuring the flow (pretty easy). Also, if you don't hear the fuel pump ticking when you first turn on the ignition, it probably isn't too healthy.
Good luck, and the car's are worth getting running - you won't find better fun anywhere (with regards to a car)!!
Regards -- Roger
-
quote:
Originally posted by ja17
Hello Dimitri,
I remember you posting about a year and a half ago. Don't get discouraged, a little persistence will pay off!
If you have a fuel tank (flower pot) problem, often times adding fuel to raise the level in the tank will temporarily solve the running problem. If your fuel level is below one half, try adding at least 5 gallons of fuel.
Joe Alexander
Blacklick, Ohio
I think that the fuel level is above one half but then again the fuel gauge has never been that accurate. I'll try adding some more fuel and see what happens. I was however under the impression that fuel entered the flower pot from the bottom so I'm not clear on adding more fuel would help unless it also enters from the top of the pot.
Dimitri
-
In addition to Joe and Roger's input, I'd be inclined to go back to Pagoda 101: take a another look at the dwell and timing, then make sure the linkage is set correctly. I'd also confirm the CSV isn't leaking. Then I'd check the vacuum and see if I could get a steady idle.
James
63 230SL
-
quote:
Originally posted by J. Huber
In addition to Joe and Roger's input, I'd be inclined to go back to Pagoda 101: take a another look at the dwell and timing, then make sure the linkage is set correctly. I'd also confirm the CSV isn't leaking. Then I'd check the vacuum and see if I could get a steady idle.
James
63 230SL
How do I check for a leaking cold start valve? I can't check dwell and timing because I really can't get the thing to run. It barely runs for a maximum of 1-2 minutes with constant easing off and pushing down on gas pedal.
-
Hello Dimitri,
The flower pot is open at the top. When the fuel level is high fuel will simply flow into the flower pot from the top. So even if the small opening at the bottom is cloged, your car would run when the fuel level is high.
Joe Alexander
Blacklick, Ohio
-
You do not need for the car to run to set the dwell. You just need to be able to crank the engine. You should also check your compression just to eliminate the possibility of a broken valve. Remove the fuel pump fuse when doing these checks and settings. Final timing adjustment can be done after you get the engine running. The dwell setting has a huge impact on how well the car will run. Research the topic on this site and you will find plenty of tips.
Frank Koronkiewicz
Willowbrook, Illinois
1970 280SL Light Ivory
-
Draining the gas tank and putting in fresh gas would be helpful too.
Plus you can check it for rust chunks in the gas that could be inhibiting flow.
1967 230SL Havana Brown Auto with A/C
-
quote:
Originally posted by doitwright
You do not need for the car to run to set the dwell. You just need to be able to crank the engine. You should also check your compression just to eliminate the possibility of a broken valve. Remove the fuel pump fuse when doing these checks and settings. Final timing adjustment can be done after you get the engine running. The dwell setting has a huge impact on how well the car will run. Research the topic on this site and you will find plenty of tips.
Frank Koronkiewicz
Willowbrook, Illinois
1970 280SL Light Ivory
Please forgive my ignorance, but do I even have to have the car running to measure dwell? My understanding of how these things work is that they read the time that the points remain closed. If the engine is not cranking then it should not work. My dwell meter is reading in the 30s without cranking the engine. The point gap is set at .012. When I crank the engine the dwell reads about 15. This doesn't make any sense to me unless the dwell meter is at fault. It is a very old Snap-On model that I've never used before.
Dimitri
-
Hey Dimitri, no such thing as ignorance here...(or I'd be in big trouble!)
That was a good question -- so I just tested my dwell meter not running and running. Not: 60 Running: 37.5. (a bit low for my liking but car is running fine)... So I'd say yes the car has to be running/cranking to get an accurate dwell reading.
This would also lead me to believe that if you are getting the 30/15 reading, something is amiss with your point gap and/or dwell. Also, I think the gap is generally closer to .016 -- which might make a difference.
PS to check Cold Start Valve. The CSV is located on the intake manifold -- there is a 7mm test screw. Remove it, place a towel underneath, and turn ignition to run, not crank, just so your hear fuel pump whining. Watch the screw hole -- you should not see any fuel coming out. I am not sure a leaky valve would cause the car to not run but it is one of the basic things to check to get things right.
James
63 230SL
-
Hi James, I actually went to Sears tonight and bought a new dwell/tach meter. I'll check it out tomorrow and report back. Incidentally I'm checking the dwell directly from the clip to where the points are attached in the distributor as suggested by other members on this forum.
Dimitri
-
Ok, so my old dwell meter was defective. The new one reads 38 with a point gap of .012. It reads 30 with a gap of .016. Car will still not run though. I'll try adding some more fuel and see.
Dimitri
-
Hi Dimitri, well I'd say the dwell at 38 is what counts (the gap is secondary)... It was probably worth double checking though -- mine basically wouldn't run when the dwell was too far off. A fuel delivery/possible debris in that small flowerpot line might be the culprit. Keep us posted...
James
63 230SL
-
Well, the fuel tank is pretty much full with 2 more gallons added but no change. The car starts and seems to run on just a few cylinders, as time goes by a few more cylinders kick in but it continues to run rough and shake. It smooths out a little if I give it a liitle more gas. If I let go of the gas at any point or give it too much gas, the car will stall. It puts out a decent amount of grey/white smoke. There is no oil in the coolant or vice versa. I don't have a gasoline engine compression tester but this might have to be my next purchase.
Dimitri
-
Haven't gotten around to compression test yet, but was wonering about the coil and ballast resistors. I've been doing some reading about them on this forum and have just been left confused. By the way the car is a 71. I replaced mine which was red with a black one - that was supplied to me by BuyMBParts. I didn't realize that there were any options. As far as ballast resistors go should they be changed with the coil as well?
Dimitri
-
Hey Dimitri. It's always been my understanding that the best set-up for our cars is the red coil (which is actually silver now w/ a red sticker) and the 1.8 ohm resistor. Most bang for the buck. I'd say its a good idea to change the resistor at same time. Both should last a long time though.
James
63 230SL
-
Check this topic in the technical manual...
http://www.sl113.org/wiki/pmwiki.php?n=Electrical.Distributor
Peter
Also known as 'admin@sl113.org' and organiser of the Technical Manual (http://www.sl113.org/wiki/pmwiki.php). Check out http://bali.esweb.nl for photographs of classic car events and my 1970 280SL.
-
quote:
Originally posted by J. Huber
Hey Dimitri. It's always been my understanding that the best set-up for our cars is the red coil (which is actually silver now w/ a red sticker) and the 1.8 ohm resistor. Most bang for the buck. I'd say its a good idea to change the resistor at same time. Both should last a long time though.
James
63 230SL
Hi James. The coil I have has a silver body with red stickers and a black bakelite or whatever material on the top. Is this the one that you are referring to? My old coil had the red bakelite material on top.
Dimitri
-
Upon further observation, my new coil is silver with black top and yellow stickers with one yellow and red sticker. Part # on box is 221 122 001. My old coil has blue body with red top. Rusty at buy mb parts has 2 ballast resistors listed on his online catalog a 0.4 and 0.6 ohm one.
Dimitri
-
Well, my coil reads 0 221 119 030. I believe the resistors come in .04, .06, .08, and 1.8. Some simply add to whatever was originally on the car (for example, my 230s had a black coil with a .09, so I could have added a .09) -- but it is easier and cleaner looking to have just the one. You might try Miller's or Ray at Bud's Benz. They should have all the varieties...
James
63 230SL
-
quote:
Originally posted by dseretakis
Upon further observation, my new coil is silver with black top and yellow stickers with one yellow and red sticker. Part # on box is 221 122 001. My old coil has blue body with red top. Rusty at buy mb parts has 2 ballast resistors listed on his online catalog a 0.4 and 0.6 ohm one.
Dimitri
Hello Dimitri,
Your coil is for the transistorised ignition system that uses both 0.4 and 0.6 ohm ballast resistors. Do you have the unit under the battery?
Here's a file with some details you can check:
http://www.sl113.org/forums/uploaded/jeffc280sl/15-20B.pdf
Hope this helps
naj
68 280SL
-
Nice save Naj. Dimitri, I may have been leading you down the wrong path on the Bosch coils -- as I was assuming non-transistorized. I sincerely apologize.
James
63 230SL
-
Thanks everyone for your input. I'll be away from my car for a few weeks. I'll resume the diagnostics then and bombard you with more questions!
Dimitri
-
Hi all. It's been a while since I've been able to get back to working on my 71 280SL which stalled out on me almost 2 years ago. I haven't been able to get it to start/run since then. At best it'll barely start and run roughly for a minute and then stall again. I have replaced most ignition components, coil, plugs, wires, condenser, cap, rotor to no avail. I have not measured the rate of flow from fuel pump but fuel does flow quite freely when I disconnect the fuel line at the CSV. I have not checked flow at the return line. I have topped of the tank with fresh fuel but that doesn't help. The car is in an apartment building garage so I haven't really been able to do much with the fuel tank. The last thing I was going to do when I last posted on this topic was check compression. Well, I did that today. The test was done on a cold engine since I can't start it to warm it up. The values are as follows: Cylinder #s 4,2,6,3,5,1 197, 199, 201, 199, 201, 200 respectively. Looks like the engine is pretty tight.
One other thing I noticed is that the .4 Ohm ballast resistor is in bad shape - cracked with a small piece or two missing. The other .6 omn resistor looks fine. Could a faulty ballast resistor cause a
hard starting/ non-running condition?
Dimitri
-
Note:
The term ''flower pot '' was coined by yours truely and is now used by all benz nuts world wide. The Dr. is happy to let this club use it with his permission.
The first thing you HAVE to do is measure fuel volume. If it's OK leave that and go to the ignition system. Pull the coil wire off and move the points with a screw driver. Place the coil wire about 1/2 inch away from a meatal part on the engine then open and close the points . You should hear a snap with a bright blue spark coming from the end of the coil wire. A weak spark with yellow or red in it won't work. Check to see if the coil wire is carbon core - something that's far more common that you might think. I'd sugest that everyone go out and check this on their car. It could save you a lot of grief knowing this and getting a steel core wire instead.
I know you said you bought new wires but a lot of these sets aren't right for these cars even though they're made by Bosch and look as though they should be OK.
Dan Caron's
SL Barn
benzbarn@ebtech.net
slbarn.mbz.org
1 877 661 6061
-
OK, so I finally performed the psi/flow test. I performed the test at the CSV connection. I performed it with and without restricting the return line by crimping rubber line just past where it leaves the injection pump. The values were as follows:
With return line restricted-> 15-16 psi and 250cc in 15 sec
Without return line restriction-> 9-10 psi and 175cc in 15 sec.
Well, it looks like a fuel delivery problem as the volume is 1/4 what it should be. Maybe I'll check fuel pressure and volume just before the fuel filter. Hopefully problem is as simple as clogged engine fuel filter or pump filter and not the dreaded flower pot.
Dimitri
-
Well, I now did a psi/flow test just before the main fuel filter and got 16 psi and 200-250ml/15sec. If the pressure is adequate then why would I have decreased flow if the two are directly proportional? Also the fuel pump draws only 3.1 amps so that seems to be ok.
Dimitri
-
Hello Dimitri,
The fuel return line is like a giant leak. You must have enough volume of fuel to return a lot of fuel to the tank and still maintain fuel pressure. Check the main fuel filter first. If it has a lot of dirt or rust in it you may have to do more cleaning further up stream!
Ignition ballast resistors seldom fail and usually work or they don't. When they fail they will go out completely. Often times as they age, the porceline will crack, but they will function until the wire coil inside breaks, then you along side the road and you will not re-start until it is fixed.
Joe Alexander
Blacklick, Ohio
-
Hi Joe, thanks for your input. I'll start inspecting the filters. Out of curiosity, would temporarily crimping the return line, and then attempting to start with now a build up of fuel to compensate for the low volume provide any diagnostic information?
Dimitri
-
Dimitri, Will it continue to run, if you squirt/spray gasoline or Quick Start into the throttle venturi/air filter? Do this carefully/safely.
-
Hello Dimitri,
Pinching the return line will increase fuel pressure only if fuel is in the system. If it is starving for fuel, the pressure will not increase. Lack of fuel is lack of fuel. Now if somehow you could increase suction then you may pull in more fuel to deliver.
Your reasoning is logical, because a increase in fuel pressure will increase volume possibly or temporarily if the fuel supply is ok. But if you have no fuel to pressurize, you will have no gain.
Check the fuel delivery system in five steps, 1)check the pressure and volume as you did. 2) check and/or replace the main fuel filter, 3) check and clean the fuel strainer in the intake of the electric fuel pump, 4)check and clean the fuel strainer/drain plug of the main fuel tank, 5) if a lot of dirt and rust is detected in the fuel tank strainer/drain, remove the gas tank sending unit in the trunk and do a visual of the inside of the tank. Clean the tank and clear the "flower pot" intake hole if needed (see "gas tank tour"). Use extreme caution around gas fumes, use sparkless trouble light, conduct procedure in well ventilated outdoors!
Joe Alexander
Blacklick, Ohio
-
Hi Glenn, I haven't tried spraying anything in the intake yet. At this point I'm in the process of checking the filters.
quote:
Originally posted by glennard
Dimitri, Will it continue to run, if you squirt/spray gasoline or Quick Start into the throttle venturi/air filter? Do this carefully/safely.
-
Hi Joe, I've started checking the filters. I jumped to the strainer of the electric fuel pump. I disconnected the hose and peered in. Without taking the fitting off, I peered in at the strainer and it seems ok. I'll take the fitting off tomorrow once I get a hold of a 27mm socket or wrench. Out of curiosity is this difficult to remove? If so I, might take the pump out and bring it to another location where I have air and try with an impact gun. I'll also check and replace the main fuel filter tomorrow. I'll have to defer delving into the fuel tank to next month since I'll be away from my car again in two days.
Dimitri
quote:
Originally posted by ja17
Hello Dimitri,
Pinching the return line will increase fuel pressure only if fuel is in the system. If it is starving for fuel, the pressure will not increase. Lack of fuel is lack of fuel. Now if somehow you could increase suction then you may pull in more fuel to deliver.
Your reasoning is logical, because a increase in fuel pressure will increase volume possibly or temporarily if the fuel supply is ok. But if you have no fuel to pressurize, you will have no gain.
Check the fuel delivery system in five steps, 1)check the pressure and volume as you did. 2) check and/or replace the main fuel filter, 3) check and clean the fuel strainer in the intake of the electric fuel pump, 4)check and clean the fuel strainer/drain plug of the main fuel tank, 5) if a lot of dirt and rust is detected in the fuel tank strainer/drain, remove the gas tank sending unit in the trunk and do a visual of the inside of the tank. Clean the tank and clear the "flower pot" intake hole if needed (see "gas tank tour"). Use extreme caution around gas fumes, use sparkless trouble light, conduct procedure in well ventilated outdoors!
Joe Alexander
Blacklick, Ohio
-
Hello Dimitri,
Yes removal of the fitting can be difficult while the pump is still in the car. If the screen looks clean, you may want to go to the main fuel filter first. Replace it and if it is dirty you may go back to the tank screen or fuel pump screen.
Joe Alexander
Blacklick, Ohio
-
Dimitri,
You could try inserting an artists brush in the opening of the fuel pump filter, move it around a bit and if it comes out clean then you should be ok.
I did this with my fuel pump when I rebuilt it. There wasn't much 'gunk' in there, just enough to say it had never been cleaned in 37years.
Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto
-
If the fuel line runing back to the tank is plugged the engine will tend to slow down and stall. It will start when cold but not run very long because the fuel needs to circulate to prevent vapour lock. You can use compresed air and blow through the line from the engine bay and you should hear bubbles in the fuel tank. Remove the fuel cap before you do this test.
If you can't blow air through the line it's plugged. Remove the line at the fuel tank return and low through the line again. If it's clear the line inside the tank is plugged. Remove the tank and get it cleaned. You can try blowing directly into the tank - this works once in a while.
Dan Caron's
SL Barn
benzbarn@ebtech.net
slbarn.mbz.org
1 877 661 6061
-
quote:
Originally posted by ja17
removal of the fitting can be difficult while the pump is still in the car.
An air impact gun will make quick work of removing the fitting on the pump while still in the car...no problem at all.
However, DO NOT use anything except a hand wrench to tighten up the fitting on reassembly.
- Mike Hughes -ô¿ô-
1966 230SL Auto P/S
Havanna Brown (408)
Light Beige (181)
Cream M-B Tex (121)
-
Well, unfortunately my car is parked in an apartment building garage in DC where I don't have air. I have air at a garage which I rent in Maryland where I do have air. Blowing out the lines is therefore not an option unless I fill one of those portable tanks with air, hmmm, good idea, maybe I'll buy one of those things. As far as the pump goes, I might have to try out the artist's brush technique or just take the pump out and bring it to my air compressor. Of course beind a northeast car the bolts that mount the pump to the bracket are rusted and will not budge. I'll just keep spraying them with penetrating oil and try my new MAC edge wrenches on them. While I'm at it I'm sanding and dissolving the heavy rust on the fuel pump cover with naval jelly.
-
I called it the flower pot because it kind of looks like one. Open at the top and a bit smaller at the bottom.
Dan Caron's
SL Barn
benzbarn@ebtech.net
slbarn.mbz.org
1 877 661 6061
-
quote:
Originally posted by dseretakis
As far as the pump goes, I might have to try out the artist's brush technique or just take the pump out and bring it to my air compressor. Of course beind a northeast car the bolts that mount the pump to the bracket are rusted and will not budge. I'll just keep spraying them with penetrating oil and try my new MAC edge wrenches on them.
Dimitri,
Please attack the easy items first! Don't hassle with removing the electric fuel pump, just do the artist brush test. You never know what is so rusty that you might break it and then you're in for more work!
First, I reccomend you perform the fuel flow/pressure test at the return line to the fuel tank. This tests the whole fuel circuit.
Second, check the main fuel filter. Very easy job and correct filters are cheap.
Third, remove gage sending unit in trunk, under plastic cap, and look in the fuel tank through the top. Use a flash light to look for rust or other sediment. If found, drain the fuel tank and remove it. You can clean out 90% of the rust flakes yourself (using garden hose nossel and lots of drying time). Remove the in-tank filter and clean around the fuel passages it uses.
Fourth, perform the fuel flow/pressure test again to see what advances you have made.
Oh, and read this tour:
http://index.php?topic=1712
Rodd
Pagoda Technical Manual
please contibute: http://www.sl113.org/wiki/pmwiki.php
1966 230SL
2006 C230 Sport Sedan
-
Rodd, would you recommend checking the flow/pressure at the fuel return line which is located in the engine compartment or the line as it enters the fuel tank? It seems as if it might be easier in the engine compartment. Also, once I crack the line open and attach the gauge to the proximal end, wont the distal end of the line start sucking in air as the pump is running? It will be a couple of weeks before I get back to working on the car so I'll keep you all posted with my progress. Thanks,
Dimitri
quote:
Originally posted by rwmastel
quote:
Originally posted by dseretakis
As far as the pump goes, I might have to try out the artist's brush technique or just take the pump out and bring it to my air compressor. Of course beind a northeast car the bolts that mount the pump to the bracket are rusted and will not budge. I'll just keep spraying them with penetrating oil and try my new MAC edge wrenches on them.
Dimitri,
Please attack the easy items first! Don't hassle with removing the electric fuel pump, just do the artist brush test. You never know what is so rusty that you might break it and then you're in for more work!
First, I reccomend you perform the fuel flow/pressure test at the return line to the fuel tank. This tests the whole fuel circuit.
Second, check the main fuel filter. Very easy job and correct filters are cheap.
Third, remove gage sending unit in trunk, under plastic cap, and look in the fuel tank through the top. Use a flash light to look for rust or other sediment. If found, drain the fuel tank and remove it. You can clean out 90% of the rust flakes yourself (using garden hose nossel and lots of drying time). Remove the in-tank filter and clean around the fuel passages it uses.
Fourth, perform the fuel flow/pressure test again to see what advances you have made.
Oh, and read this tour:
http://index.php?topic=1712
Rodd
Pagoda Technical Manual
please contibute: http://www.sl113.org/wiki/pmwiki.php
1966 230SL
2006 C230 Sport Sedan
-
Well, I'm back to tackling my non-running 280SL. Over the past 2 days I replaced the main fuel filter in the engine compartment. It looked like it hadn't been changed in a while but otherwise didn't seem to be particularly dirty. I put an air gun nozzle to the return line as it exits the engine compartment. It seems to be patent as I heard bubbles in the fuel tank. I removed the small 6mm bolt on the side of the CSV and turned ignition to #1 position. No fuel leak. The CSV has power as tested with a test light while cranking the engine. Next thing I'll do is spray some starting fluid into intake. If car runs then I'll delve into the fuel tank-a task which I've been dreading.
Dimitri.
-
I drove my 230SL only a very little bit when I first got it. Then it spent the next five years on the patio while I rebuilt the rusted out floor and cross members, and I'm only now beginning to drive it again. It had always started very hard and needed a lot of gas pedal to keep it going until warm. It would also stall and part of the problem was loose rust that would gather in the sump of the fuel tank, around the filter, the "flowerpot." I've removed gobs of this with a magnetic pickup tool (rust flakes are still are mostly iron).
Once I got the car back together enough to drive it (that was about two weeks ago), it was starting harder than ever and soon it wasn't starting at all. I separated the CSV from the intake manifold and saw that with the ignition on, it was leaking in a continuous fine spurt. I removed and cleaned it, and that fixed the leak, but the car still wouldn't start. I checked the WRD (warm running thermostat) on the injection pump, which performs the same function as the choke and fast idle on a carbureted engine. I'd checked it once before and found a lot of corrosion, which I cleaned out. Checking it again, I found that cleaning hadn't been enough: the value was stuck closed. I got it loose with a slide hammer, then cleaned and oiled it so it would move up and down with the thermostat. This should have fixed the cold start and warm-up problem, but the car still wouldn't start. So I pulled all the spark plugs, cleaned them, and ran them under hot water to warm them up (I don't know why this helps, but it usually does). The car finally started and better yet, it started and stayed started since the WRD was now working for the first time.
Suggestions:
1. First conquer your fear of the fuel tank and do the magnet test/clean, it's really the easiest of the jobs I've described and you don't even need to drain any fuel. (Don't use the wimpy tool that looks like a car antenna, use the heavy-duty one with the snake neck.) While you're at it, it's worthwhile to check for water in the same place, using a turkey baster. If what comes out forms drops on a surface, there's water.
2. Test the cold start valve by separating it from the manifold with everything still connected. See if it squirts or dribbles fuel with the ignition on, then manually activate it by jumpering to the battery to see if it sprays properly like an aerosol. (Don't touch the live wire to the valve terminal, there will be a spark, clamp the disconnected wire to it, then make contact at the battery terminal. Or use a remote start switch.) If it leaks or doesn't spray properly, remove and clean it.
3. Remove the thermostat part of the WRD and check to see that the valve isn't stuck closed and moves up and down with the thermstat action. (It's a piston-type valve.) If not, remove and clean it as I described above. Then you'll know you have your choke and fast idle functionalty.
4. When the car still won't start, try the spark plug clean-and- warm I described.
P.S. Congratulations on your compression. Mine's about 135 straight across.
-
I sprayed starting fluid in the intake and it didn't change anything. The car would run roughly for a minute or so with an occasional backfire while keeping the gas pedal partially depressed and then stall. I took out the fuel sending unit and peered into the gas tank which looked remarkably clean with bright shiny metal. I could see the opening at the base of the flower pot which also appeared clear visually. Also, the last time I checked fuel pressure and volume I used a pressure gauge which had an outlet for checking flow. Using this I got a flow of 250cc/15sec. Wondering if the fuel gauge was in anyway restricting the flow, I decided to just put a hose on the fuel line at the CSV. From there I measured about 600cc/15 sec which is much better but still less than the required liter. So, here I stand contemplating what to do. I have a fuel tank that looks pretty darn clean, but a suboptimal flow rate with good fuel pressure. I guess draining my clean tank to get to the in tank filter which will probably be clean should be the next step. I was also thinking that maybe the fuel pump is not strong. But again I had checked current at the fuse which was 3.2A.
-
Hello,
You might want to check and make sure the rack on the injection pump is not stuck.
Joe Alexander
Blacklick, Ohio
-
Something doesn't sound right about the symptom's related directly to the fuel lines or fuel tank issues (clogged lines, etc). The fuel filter at the engine is a cup which fills with gas no matter whether there's a low flow or semi-clogged line or filter at the tank. Turning on the ignition (not starting the engine) activates the fuel pump and forces whatever fuel is getting thru to the fuel filter which eventually fills up unless there's an absolute clog with no fuel getting thru at all.
Therefore, when starting the car after letting the fuel filter cup fill up, it should start fine with no stumble's just as it did before the problem started, no? It would only stall when the cup runneth dry.... UNLESS the problem's somewhere between the fuel filter and injectors at the intake.
So, despite the lower than normal flow rate described, the flow rate should be more than sufficient for a smooth idle for any duration (given any gas in the tank).
When I finally took my car out of the garage (16 years sitting idle) and had engine rebuilt, etc, it sat idling at the shop for quite a while, then I drove away and after about 6 miles the engine sputtered and died. It restarted again easily right after I coasted to a stop.... about 60 sec's worth... but stalled again right after I got going again.... maybe drove 100 meters. I kept this exercise up several times until I was able to get off the free-way and onto a side street. While walking a couple of blocks to a phone (I didn't have a cell at that time), calling the shop and telling them to send a tow truck and come pick it up, and getting back to the car, it started right up again... and I drove it 2 blocks without a hiccup to the service station where the tow truck would pick it up.
It turned out to be a rusty fuel tank and sufficient fuel was getting thru for slow speed (low rpm) driving, but step on the throttle to accelerate to 60 and before it got there the engine was being fuel starved and died. The initial observation that I could wait a couple of minutes and start it up again and drive it another 100 meters was related to the fact that that's how much fuel was in the fuel filter cup... and the fuel filter was now nearly fully clogged.... so fuel would only be forced thru it by 'seeping' thru whatever remaining pours there were.
My point is that even with a dirty tank and rust galore, the car should start up and idle without any issues at all after giving the fuel enough time to seep into the fuel filter cup and fill it... even IF the fuel line's nearly completely clogged between tank and filter.... so the symptoms described indicate a problem between the filter and engine intake... not primarily with something between the tank and fuel filter.
Have you checked for proper operation of the cold start value (cooling water thermostat) which controls the fuel/air mixture on starting and adjusts continuosly as the water temperture increases, eventually leaning out the mixture at water temperature 65-68C. It doesn't sound like the time over which the car starts and then stalls is very long (less than a minute?... I haven't seen any time from start to stalling in the thread) so the water temperautres assumedly never getting very warm. If the mixture's rich enough to start, but stay's too rich to remain running then perhaps the thermstat valve's stuck in the 'rich' position.
Also, fyi, the fuel delivery system delivers far more fuel at all times than is needed for full throttle operation, so even with the flow's you've described, there should be more than ample fuel to remain at idle.
Also, an admittedly absurd suggestion, but since you've done the spark (ignition) bit already.... it's down to a fuel or air problem. Focus has been on fuel... but have you checked the linkages to the venturi and assured it's opening properly? Apparently while driving along just fine the problem suddenly caused the car to die and you haven't been able to keep it at idle ever since... so 1st pass analysis says something got broke or stuck and is staying stuck.
BTW, what year/model is the W113 you're referring to?
Longtooth
67 250SL US #113-043-10-002163
The 6% Club - Best of the Best
'02 SL500 Sport
-
Joe, I read through the injection pump tour and you mention that on later pumps (my car is a '71) "the rack end has an m4 threaded hole on all except the latest pumps which were solid". What do you mean by this? Is there a different method for checking the rack on a 71 280SL? Also, I thought that a stuck rack was something that happened from inactivity or dirty fuel. As Longtooth mentioned, my car just stalled out as I was driving home suggesting that something broke. Thinking back to that day I even recall checking the fuel pump fuse which was burned out. I replaced it, the fuel pump started working but the car still wouldn't start. This whole thing is just getting too strange.
Dimitri
quote:
Originally posted by ja17
Hello,
You might want to check and make sure the rack on the injection pump is not stuck.
Joe Alexander
Blacklick, Ohio
-
Dimitri,
Assuming something got stuck or broke, rather than a fuel delivery to the injector pump problem, have you checked the venturi? If it's stuck or the spring broke then....?
In general diagnosing a problem to it's source is either very, very simple, or not (duh). In your case I think it's long since past the simple type diagnosis.
When a problem doesn't lend itself to a simple diagnosis of it's source,the only option is to use a rigorous approach. You've already gone thru the ignition issues (plugs, points, condenser, coil, wires from distributor to plugs), so that leaves fuel / air.
On the fuel side, the rigorous obvious question is whether fuel's getting to each of the intake ports continuously for sufficient duration to maintain an idle and then increase with throttle applied. Less rigorously, and st the question is whether fuel's coming out of the injector pump ports on schedule. Basically, these questions apply to whether the pump's operating properly....
On the pump questions, at least one of the auxillary funcitons related to the "pump" is at the CSV... I already posed the question as to whether the Cold Start Valve is working as it should, since this controls the fuel (leaning it out from an initially rich mixture as water temperature increases).
For air, it boils down to the air intake filter or the venturi I think. I'd personally have difficulty believing that the air intake filter is problematic, but the rigourous approach to diagnosis starts there for air. If not that, then the venturi.
One thing which might help in diagnosis is more detail related to starting and idling:
1. How long the engine can idle without throttle applied (beyond perhaps the initial startup throttle applied --- though I don't use any throttle on starting up).
2. Does it initially idle without fits? and if so, how long after initial good idlel before it starts hiccuping or simply coughs and dies?
3. How far and for how long had you been driving since it's most recent immediately preceeding start-up when the engine died the last time you drove it?... and was it cold outside or just a balmy DC 55 degr F?
4. How long had you driven the car (& how many times) before that last drive?
5. Had you ever noticed any starting problems before... mild or not so mild ones?
6. How long (how often had you driven) after the previous mechanic's (or self) "tune-up" had occurred?
Longtooth
67 250SL US #113-043-10-002163
The 6% Club - Best of the Best
'02 SL500 Sport
-
Longtooth,
The venturi seems to work fine it opens and closes freely.
Without physically observing the function of the CSV, it works. That is, there is no leakage from the bolt hole on the side of the valve once the bolt is removed and a test light lights up upon cranking the engine. I do plan on removing the CSV and observing the flow of fuel first hand.
I'll try to answer all the other questions:
Q 1. How long the engine can idle without throttle applied (beyond perhaps the initial startup throttle applied --- though I don't use any throttle on starting up).
A The engine will not idle at all without applied throttle. I have to keep throttle applied just enough to keep it running, too much or too little and it will stall.
Q 2. Does it initially idle without fits? and if so, how long after initial good idlel before it starts hiccuping or simply coughs and dies?
A It never has good idle. After 15 secs and a little more throttle, the idle will smooth out a bit but the car will put out a profuse amount of white/gray smoke and then backfire a few times.
Q 3. How far and for how long had you been driving since it's most recent immediately preceeding start-up when the engine died the last time you drove it?... and was it cold outside or just a balmy DC 55 degr F?
A The last time I drove the car, I was using it as a daily driver for 3 months. About 20 miles per day with some a few miles being highway. It was probably around 65 degrees F.
Q 4. How long had you driven the car (& how many times) before that last drive?
A As above. I have owned the car for 11 years. It has gone back and forth from being used one or twice a month to being a daily driver for a few months to a year at a time.
Q 5. Had you ever noticed any starting problems before... mild or not so mild ones?
A The car always started well except for when it needed new points or a point adjustment. It has had one major overhaul. I hate to admit this, but while in medical school and worried less about my car than my studies, I was not keeping track of engine coolant level. This car at the time did not have a functioning temp gauge. Well, one evening, I was driving on the highway when suddenly, poof. A mist of coolant in my face and the car stopped running. I pulled over, popped the hood and there you have it. The car over heated, and warped the head.
That was in 2001. The car got the head replaced with a rebuilt one and had been running fine ever since.
Q 6. How long (how often had you driven) after the previous mechanic's (or self) "tune-up" had occurred?
A Last tune up had been performed by a mechanic about 8 months prior to when car was last running. I don't believe much beyond points.
Dimitri
quote:
Originally posted by Longtooth
Dimitri,
Assuming something got stuck or broke, rather than a fuel delivery to the injector pump problem, have you checked the venturi? If it's stuck or the spring broke then....?
In general diagnosing a problem to it's source is either very, very simple, or not (duh). In your case I think it's long since past the simple type diagnosis.
When a problem doesn't lend itself to a simple diagnosis of it's source,the only option is to use a rigorous approach. You've already gone thru the ignition issues (plugs, points, condenser, coil, wires from distributor to plugs), so that leaves fuel / air.
On the fuel side, the rigorous obvious question is whether fuel's getting to each of the intake ports continuously for sufficient duration to maintain an idle and then increase with throttle applied. Less rigorously, and st the question is whether fuel's coming out of the injector pump ports on schedule. Basically, these questions apply to whether the pump's operating properly....
On the pump questions, at least one of the auxillary funcitons related to the "pump" is at the CSV... I already posed the question as to whether the Cold Start Valve is working as it should, since this controls the fuel (leaning it out from an initially rich mixture as water temperature increases).
For air, it boils down to the air intake filter or the venturi I think. I'd personally have difficulty believing that the air intake filter is problematic, but the rigourous approach to diagnosis starts there for air. If not that, then the venturi.
One thing which might help in diagnosis is more detail related to starting and idling:
1. How long the engine can idle without throttle applied (beyond perhaps the initial startup throttle applied --- though I don't use any throttle on starting up).
2. Does it initially idle without fits? and if so, how long after initial good idlel before it starts hiccuping or simply coughs and dies?
3. How far and for how long had you been driving since it's most recent immediately preceeding start-up when the engine died the last time you drove it?... and was it cold outside or just a balmy DC 55 degr F?
4. How long had you driven the car (& how many times) before that last drive?
5. Had you ever noticed any starting problems before... mild or not so mild ones?
6. How long (how often had you driven) after the previous mechanic's (or self) "tune-up" had occurred?
Longtooth
67 250SL US #113-043-10-002163
The 6% Club - Best of the Best
'02 SL500 Sport
-
Here is an update. I checked the CSV first hand. I removed it from the intake manifold and turn ignition to #1 position. There was no leaking from the orifices of the injector nozzle. I then cranked the engine and observed the spray pattern. It was a nice mist from both orifices. By the way the gasket between the intake manifold and the CSV came apart when I removed it. I ordered a new one from the local stealership. $9!
I then proceeded to check the rack on the injection pump. On this car the end of the rack is not threaded so I just pushed on it with a brass punch. The rack moved freely and sprung back easily.
Dimitri
'71 280SL
-
Dimitri,
In reading your well answered responses to my questions, I'm now perplexed as to why/how the problem focused on a fuel delivery issue? Though that's still one of the possible reasons the idling symptoms don't sound like a fuel delivery source to me.
In particular ---
- car ran just fine all warmed up and everything, with no idle problems, then just dies while driving down the road.
- thereafter idle is poor and difficult to maintain at all, and then only by careful throttle... too much or too little it dies.
- fuel in the final filter container would let car idle from start without issue even if fuel delivery from tank were extremely poor... so not a fuel problem in delivery from tank to pump.
- you get smoke after maintaining a poor idle for 15 sec's or up to a couple of minutes ... with backfiring too boot.
quote:
It never has good idle. After 15 secs and a little more throttle, the idle will smooth out a bit but the car will put out a profuse amount of white/gray smoke and then backfire a few times.
My first inclination is to think these symptoms sound like a valve timing problem.
The backfire occurs with an ignition during or near the start of the exhaust stroke (intake, compression, ignition, exhaust). This indicates the spark (ignition) occurs too late (too retarded) or way too far advanced relative to valve timing (ignition occurring too early in compression stroke so intake valve isn't completely closed... so not technically a back-fire from the exhaust but backfire into the intake manifold)... or put another way, spark's too retarded, or exhaust valves opening too soon or aren't closing far enough.
Have you checked compression? ... which would indicate a valve timing or seating, or valve guide leakage problem if it exists --- though you wouldn't be able to distinguish from warn compression rings.... the symptoms would allow you to focus on the valves.
What's the state of your timing chain? How many original miles on the cam sprocket and timing chain?
Was the cam replaced when the head was overheated, warped and replaced?
My thinking runs like this --- it starts but idles with difficulty .. probably (my guess) having to add a little bit of throttle to maintain an idle as time goes on. The white/grey smoke at the end, before it finally stalls out sounds like incomplete combustion ...i.e. ignition occurring too late in compression cycle or after exhaust valves open (or if poorly seating). This symptom is consistent in reason with the backfire symptom. The reason this doesn't occur immediately on starting probably (just my guess) has to do with combustion chamber and valves heating up while trying to maintain an idle.
I see no reason why a fuel delivery problem to the engine would
1) cause a poor idling condition in the 1st place (unless some cylinder's were getting fuel and others not), &
2) create grey/white smoke as fuel depleted, &
3) force a final back-fire or two before engine died.
Furthermore, you've now checked the CSV's function and find no issues, so sounds like it's either fuel timing (injection timing) or valve timing. .. .and fuel timing should be constant and wouldn't suddenly change to cause back-firing.
So my curiosity is aroused as to how and why a fuel delivery issue is or has been the primary diagnosis thus far?
An expert on these symptoms and causes with the W113's should chime in at this point.
I'm not an expert on this by any stretch though --- I've worked on VW & Porsche engines years ago (rebuilt them from scratch), my truck's former 283 & now 327, but not on the W113's. My primary experience with valve timing comes from playing around with my 327's valve timing and ignition timing combinations.... advancing (mostly) or retarding things (by error) to maximize acceleration and power at the expense of fuel efficiency. It was during those experiments that I frustrated with poor idling, grey/white smoke, etc.... and I was working with my 327 with unknown but umpty-ump gazillion hard miles on it, and my old high compression heads before I decided I had to have the entire mess rebuilt from the ground up. I'm also not a gear-head.... I worked on the VW engines for want of money to pay anybody else to fix the one I nearly melted.. initially for economic necessity as I'd never, ever done anything more with an engine that put oil and water in them. I worked on Porsche engines for a couple of friends (356's) because they're no different from VW engines in principle, and it was just fun in my spare time (this was after I'd attained a level of economic freedom). I worked on the 283 and 327 engines in my truck because I wanted to learn more about water cooled big ("real") engines and systems... and again it was for fun and learning (by which time I could easily afford to have somebody else do the work... which I eventually had them do... built from scratch to my spec's).
I've timed my W113 myself a couple of times, and will do so more often now that I retired, but getting the engine to tdc (or where-ever I was supposed to get it) is a **** compared to VW's and GM engines.... and neither of those have to deal at all with fuel delivery timing.... just the mixture. I'll offer that my distributor is the car's original Bosch and that the rotor shaft cylinder bore is slightly warn, hence I have to offset my static timing slightly to get the dynamic timing right... the bore wear causes a bias in point set point compared to after driving the car around the block. The offset's not enough to hardly matter and I can't really notice the difference except under a hard accelerations.... certainly not at idle.
Longtooth
67 250SL US #113-043-10-002163
The 6% Club - Best of the Best
'02 SL500 Sport
-
Hi Longtooth,
I've been also started to think along the lines of a timing problem.
Here are some answers to some of your other questions:
Have you checked compression?
-Yes, the compression is about 200 psi across the board.
The values are as follows: Cylinder #s 4,2,6,3,5,1 197, 199, 201, 199, 201, 200 respectively. The numbers seem a little high. Perhaps due to the rebuilt head being machined.
What's the state of your timing chain? How many original miles on the cam sprocket and timing chain?
-I don't know the answer to any of these questions. When I bought the car it did not come with any records. Only thing I know is that some guy from New Jersey was the previous owner. The car was bought from Gullwing Motors in LIC New York for $16,000 back in 1997. The car has undocumented mileage. I'm guessing 150,000 miles.
Was the cam replaced when the head was overheated, warped and replaced?
-I don't know. I just took a look at the receipt and it mentions a used head, fan clutch, head gasket, valve cover gasket, spark plugs, etc... but not mention of camshaft.
I'm wondering if I'm not missing something really obvious like a crossed plug wire or something. As far as timing goes, I'll try to check it. It'll be challenge since my girlfriend will have to keep the car running for that short time while I perform the test. I've tried this before and she wasn't able to to finesse the throttle enough to keep the engine from stalling.
Dimitri
-
Demitri,
Also check the throttle linkage to the venturi.... take a look at the thread on this forum related to it.
Compression value units are important if all cylinder's have a common valve seating or value guide problem.... but not if any one or a few do.... then only the differences are important. From your compression data it looks like all 6 cylinder's are behaving the same... so all are either good or all are similarly bad. That's a good thing.
I don't know how much you know about timing an engine, so pardon me if this is pendantic. Setting the point gap is done with the the valves at a specific position in the 4 cycle engine (tdc at cylinder number x). If there's slop in the timing chain (which is common.... just a matter of degree), then you have to get the valves to the set-point (say #1 at tdc for example) by turning the engine only in it's normal direction of rotation. If you overshoot you can't just back up a bit... you have to go all the way around again... but without overshooting the mark. There may be 2 highlighted (usually white) marks an the counterweight... one being the tdc point, the other being the advance or retard offset point.
Since you've set timing before with no problems I assume you're using the correct procedures, but mention the above since sometimes luck has to do with it... and since something's changed (while driving the car to cause it to stall) it's imparative that the the smallest departures be noted --- since it's not always clear that the smallest departures aren't the culprit until after the fact of finding the cause(s).
Longtooth
67 250SL US #113-043-10-002163
The 6% Club - Best of the Best
'02 SL500 Sport
-
Yikes! I priced the small rubber/plastic cap in front of the injection pump that covers the end of the rack yesterday. $140 at the Bethesda dealership, $107 from Rusty! Why is this part so pricey! Treat this part with respect when you remove it as insignificant as it may seem. When I pried it off it started to crumble from age so I have no choice but to replace it. I'm wondering if the injection pump rebuild shops have another cheaper source for this part which in my opinion should cost no more than $5-10.
Dimitri
-
Does anybody know if there is supposed to be a mark on the aluminum distributor body that designates where the wire to the number one cylinder goes? I'm asking because I see a number one stamped into the distributor but that does not correspond to where the #1 wire goes. It is actually next to where the #1 wire is attached to the cap. I figured maybe I accidentally rotated all the wires when I replaced my cap and wires 2 years ago. To make sure I re-attached the wires so that they would correspond to this mark on the distributor but things only turned
out worse. The car does not start at all now. Before it would start but not run. Does anyone know what this mark represents?
Dimitri
'71 280SL
-
At this point I would start from scratch:
1.) Remove the spark plug wires and all spark plugs.
2.) Remove the distributor cap.
3.) When turning the engine clockwise, note the direction of rotation of the distributor rotor. Turn the engine by hand until the #1 piston is visible at the top of its travel through the spark plu hole AND the timing mark on the front pully is at the 0 degree indicator. You have now achieved top dead center (TDC).
4.) Check the distributor cap to see if #1 plug wire is inserted on the cap adjacent to the position of the rotor. If not pull off all of the plug leads and put #1 lead on the proper lug on the cap and then insert the remaining leads, following the firing order embossed on the valve cover, in the direction of rotation.
You should now at least have the ingnition lead position and firing order back to normal. Replace the plugs, reattach the plug wires and reinstall the distributor cap. If the car was running before you changed the wires around on the cap it should be running at least as well that now - maybe better, if the firing order was incorrect before.
- Mike Hughes -ô¿ô-
1966 230SL Auto P/S
Havanna Brown (408)
Light Beige (181)
Cream M-B Tex (121)
-
I put the wires back to where they were initially and the car starts again. They are now where they were when the car was running 2 years ago. What does this mark on the distributor represent, I wonder?
Also, I checked timing and it is set at about 10 deg BTDC but the plate on the car says it should be 8 ATDC at idle speed. This doesn't make any sense to me. When the car was running it must have been set at 10 BTDC since I haven't adjusted anything.
What about the ignition modules, do they have a habit of failing on these cars? I know I'm reaching.
Dimitri
-
OK, I clarified the mark on the distributor. I don't know what it means but the correct mark that designates the #1 wire is actually on the rim of the distributor, not on the outside. My wires are in the correct position as the #1 wire location coincides with the mark. I'll try playing around with the timing and see what happens.
Dimitri
-
I played around with the timing by turning the distributor back and forth. It didn't help any, the engine ran better or worse depending on how much I turned it but overall no change. The car still runs rough, will stall once the throttle is released and continues to put out much white/grey smoke. An interesting observation was that the timing light would not fire on the first cylinder when the plug boot was in place. However, when I pulled the boot and let it arc against the valve cover, the light would flash. I made the same observation with the #5 wire. In the meantime the building management is starting to complain about smoke levels in the garage so I can't continue this much longer. I'm thinking about just getting the thing towed to a mechanic and getting this over with.
Dimitri
-
Dimitri - I don't in the least blame you. You don't have prominent in your family tree anyone named "Job", perchance? Ahhh;"Ulysses"!?!
Alas, I am another member outclassed by your challenges. Am now holding out some hope that the ignition oddities you've just noted might mean something to wiser heads and not just indicate plug fouling from all the crappy running. Have you seen them lately? No, I don't mean to imply they're causal, just that they may be getting so fouled as to muddy the situation. Probably wouldn't hurt to pick up a couple of sets, leaving you poised to drop in fresh ones when any headway begins to be made.
(At least one Wise Head is swamped at his day job these days, worse luck.)
I live outside DC, toward Baltimore, and could lend hands or a feather-foot if the need becomes great. (Have wrenches and such too, left over from another life; sure wish now that it had had a lot more to do with Mercedes.)
Better luck,
Denny
-
If you are getting arcing to ground with the plug wires pulled but no signal on an induction timing light when they are snug on the plug I would replace all six plugs with new NON-RESISTOR plugs. Someone chime in if I am wrong on the Bosch plug number: W7DC or W9DC if you need a hotter plug.
- Mike Hughes -ô¿ô-
1966 230SL Auto P/S
Havanna Brown (408)
Light Beige (181)
Cream M-B Tex (121)
-
Dennis, I was also thinking about replacing plugs with "newer ones"
I might take you up on your offer of assistance. My car is in DC where I live but I also rent a garage in Silver Spring where I'm working on my 220D. I'm back and forth from Boston so I tend to be away from my cars for 2 week periods or so.
Dimitri
quote:
Originally posted by 3-point roadster
Probably wouldn't hurt to pick up a couple of sets, leaving you poised to drop in fresh ones when any headway begins to be made.
(At least one Wise Head is swamped at his day job these days, worse luck.)
I live outside DC, toward Baltimore, and could lend hands or a feather-foot if the need becomes great. (Have wrenches and such too, left over from another life; sure wish now that it had had a lot more to do with Mercedes.)
Better luck,
Denny
-
Mike, please forgive my lack of spark plug knowledge. Are you saying that I might need a hotter plug? Also, what are non-resistor plugs?
Dimitri
quote:
Originally posted by Mike Hughes
If you are getting arcing to ground with the plug wires pulled but no signal on an induction timing light when they are snug on the plug I would replace all six plugs with new NON-RESISTOR plugs. Someone chime in if I am wrong on the Bosch plug number: W7DC or W9DC if you need a hotter plug.
- Mike Hughes -ô¿ô-
1966 230SL Auto P/S
Havanna Brown (408)
Light Beige (181)
Cream M-B Tex (121)
-
Dimitri,
Typically, resistor plugs have a resistor built in and is mainly used for interference supression (on modern engines with computer controlled ignition/fuel injection).
Non-resitor plugs have no resistor and is the preferred plug for use on our engines.
Depending on the manufacturer, NGK or Bosch, resistor plugs will have a R in the number.
For example, Bosch WR7DC would be a resistor plug and the W7DC would be the non-resistor variant. Or, NGK BPR6ES for resistor and BP6ES for non-resistor.
With regards to the heat range of the plugs, again it depends on the manufacturer. With NGK, the lower the numerical value of the plug, the hotter it is ( eg. A BP5ES will be hotter than a BP7ES).
With Bosch, it is the other way around - the lower the numbers, the cooler the plug (eg. a W7DC will be cooler than a W9DC).
There are quite a few posts on the sparkplug issue, just do a search.
Which plugs are you using at the moment?
Regards,
Jaco van der Walt
1964 w113 230sl
1975 w114 230.6
-
Dimitri -
In all your postings there is little information on the state of your engine prior to your starting difficulties. If your plugs foul easily (oil consumption or rich fuel mixture are two common causes for plug fouling) you might want to try a hotter plug. It is not unknown for a plug to fail internally and just not deliver spark (it's happened to me!) so changing all your plugs may be an inexpensive means to eliminate this as a cause for your starting and running problem. Check all of your plug wires for sparking to ground like you checked the #1 wire earlier to eliminate a bad plug wire as the culprit. Also check the contacts on the plug wire ends to insure that they grip the plug firmly.
- Mike Hughes -ô¿ô-
1966 230SL Auto P/S
Havanna Brown (408)
Light Beige (181)
Cream M-B Tex (121)
-
Mike, the car doesn't burn any more oil than normal. It probably does run a little rich as I can smell gas in the oil. I did actually check all other plugs with the timing light. The light flashes when attached to all wires except numbers 1 and 5. I also removed #5 wire from plug and it sparked to ground. The timing light flashed when I did that. These plugs are new in the sense that they were replaced when the trouble started . I removed them again a little while ago when I checked compression and they were not particularly fouled. I'll report back on the model of NGK plug I used. I'm away from my car for 2 weeks again, so I'll have my girlfriend read the numbers off of the box. I suspect they are the non-resistor type. If that is the case then like you say a hotter plug might help.
Dimitri
-
Well, it turns out that the plugs are Bosch Super 7500 WR7DC+. From what you've all said it is not a proper match for this car. I'll swap them with either non-resistor Bosch or NGK plugs and see what happens. It would be great if this simple fix solves the problem!
Dimitri
71 280SL
quote:
Originally posted by dseretakis
Its been over one and a half years now that my 280 SL will not run. It started when I was driving home and the car just stalled and would not restart. I pushed it into the garage of my apartment building where it has sat eversince. I figured it was probably ignition related as there was fuel coming from the fuel line going to the intake manifold when I disconnected the line. I did not however measure the rate of flow. I proceeded then to replace the points, rotor, cap, condenser, wires, plugs and got the car to start, run poorly from anywhere from 15 secs to up to 2 minutes and then stall again. I gave up and left the car that way for 1.5 years. I figured that maybe the ignition coil was bad so I replaced it today. Again no change. It runs poorly for 30 secs to a couple of minutes while giving it a good amount of gas and then stalls. I'm at a loss. I don't wan't to just keep replacing parts. I'm starting to suspect the fuel system again. Any ideas? Thanks,
Dimitri
-
Demitri -
Dominant symptoms remain the same:
1. Car died while driving along with no prior starting or other engine symptoms.
2. It starts but runs irregularly and only briefly with careful throttle control, then dies again within 15 sec's to 2 minutes.
3. When started, it spews white/grey smoke profusely.
The white/grey smoke indicates incomplete combustion.. either too much fuel, too little air, insufficient ignition spark (not likely if any spark at all), timing, or valves not operating properly.
Whatever occurred happened while driving along.... so it's something that slipped, broke, or wore out beyond ability to remain within operating range.
It starts, so you're getting spark... that eliminates plugs, coil, ignition circuit as probable source. I run Bosch resistor plugs in my 250SL... always have... no problems.
You've moved distributor body back and forth to change timing and it still won't stay started. That eliminates timing issues as probable source.
You've checked ignition wiring order and for fouled plugs.... no issues found.
You've checked fuel delivery from back to front... no issues with insufficient fuel.... and since it starts but runs irradically, fuel delivery to cylinder intake isn't the primary suspect...
... unless your injection timing is screwed up... would require injection pump overhaul and possible rebuild if this is the case.... would fit the symptom of car dying while running along (something in the pump (injection cam? cam bearing?) broke, slipped, or wore too far), but not the symptom of white/grey smoke emissions while starting. ...
... or unless the injection pump's delivering too much fuel per stroke.... which would fit both symptoms.... something broke, slipped, or wore beyond range, and white/grey smoke.
Valve seating or opening/closing is still open to possible source of problem, however. Valves (intake and exhaust) are normally closed (by valve springs)... they open when the rocker arm forces them open... overhead cam direct to rocker arm actuates the rocker arms... pushing "down" on the valve stem, opening them the "required distance" from valve seats. The "required distance" of valve opening is adjusted by adjusting the clearance between cam lobe and rocker. The clearance is adjusted at the "ball pin head"... i.e. the rocker arm standoffs opposite the valves... on the respective rocker arms.... when cam's lobe at a given valve is 180 degrees opposed to the rocker's sliding (contact) surface to cam.
If cam lobes or rocker arm surfaces are worn (or as they wear), the clearance between them effectively increases, and valves don't open as far... they open later, and less, and close early. When ignition timing's set at spec (8 degr BTDC at starter speed or at idle, without vacuum) a later opening intake valve means ignition is relatively even more advanced than 8 degr... which shouldn't cause incomplete or inefficient combustion, but will cause the piston to be resisted longer during the exhaust stroke. This would cause a reduction in hp, but otherwise doesn't fit the symptoms.
As the valve seats wear in (if they do, as on a new head rebuild with new valves & seats), the opposite occurs... there's not enough clearance ("too tight" - cam to rocker) so the valves open early, more, and close later. This means on the intake stroke the intake valve opens earlier than fuel injection timing requires, and ignition occurs relatively later wrt valve's being closed on the compression stroke... in effect a more retarded ignition wrt intake valve closure (normally closes at 11 degr BTDC with normal ignition at 8 degr BTDC ... with ignition advanced more with vacuum at higher rpm's). The exhaust valves open earlier as well... meaning an additional portion of the relatively later ignition combustion products are being exhausted before combustion is as complete as it would otherwise be. This fits with the incomplete combustion symptom, so remains a possible problem source.
Parenthetically, after my engine was rebuilt (long block), at about 3k miles the engine began to be hard starting and ran rough at idle... and after checking timing (gap, dwell, & timing hadn't changed much at all), I ran a compression test and found cylinder #1 was slightly lower than the others, but not enough to account for the rough idle and hard starting issue (it had been far, far worse before I had the engine rebuilt and at that time it had no hardstarting issues and didn't run rough at idle). So... I took it into the MB shop and they found valves had worn in on the seats and valves needed adjustment for having been "too tight".... i.e. I only mention this because a small amount of wear-in on the valves and seats has a definite effect on rough idle with no other apparent symptoms of a problem. It turns out I was supposed to take the car back for a valve adjustment at 1500 miles and again at 3k miles for precisely this reason.... which I'd forgotten about.
If a valve spring breaks, there's nothing holding the valve normally closed, so it's always going to be open a little (more or less) ... and the rocker's will open them more perhaps but in effect you'ed have too little compression on such a valve. You've indicated that measured compression is even on all cylinders... so that eliminates any broken valve springs as possible source.
Have you checked &/or played with the idle air screw on the venturi?... maybe the passage got clogged somehow. Before you adjust it make sure you mark where it is to start with though.
Frankly, you have far, far more patience and persistance than I would have under the circumstance. I'd have checked (not necessarily changing) timing, compression, venturi idle air adjustment and operation, fuel linkages, plug's gap and condition, and decommissioned the cooling water thermostat (so it's functioning as if cooling water temp was hot (> 68C) to see if it was actually inop at starting temps (not just the themostat's rod, but the mechanism the rod actuates to enrich fuel and air during starting temperatures). If I could find no problems with any of those items I'd have had the car toted to the shop... though since I'm now retired I would have perhaps also taken the time to check the valve tappet clearances.
In my experiences on the car's I've ever worked on / played around with engines on... VW's, Porsches, GM 327's, if the car will start but won't hold an idle it's either been due to wiring (improper order of spark plug wires from roter to cylinders), timing or fuel / air mixture... but I've never had an opportunity to play around with a fuel injected engine and I'm loath to play around with the one on my 250SL... too chicken. The W113's fuel / air mixture at starting tempertures is controlled by the mechanism actuated by the Cold Start Thermostat... just because the thermostat works (rod moves appropriately with temperature) doesn't mean the mechanism it's actuating is working properly.
Longtooth
67 250SL US #113-043-10-002163
The 6% Club - Best of the Best
'02 SL500 Sport
-
Did you ever clean the gas tank, blow the lines clean, new fuel filter up front and in the tank etc? I had a van that ran ok parked but driving caused a blockage in the fuel delivery from gunk in the system.
You could be getting decent flow parked until the junk gets sucked into an orifice someplace. When the engine gets turned off it floats away again.
Stabbin in the dark
-
Well, it's 3 months later and I've been able to get back to my car. The first thing I did was change out my resistor Bosch plugs with non-resistor NGK ones. This solved a big part of my problem. The car now runs smoothly on all 6 cylinders rather than 3 or 4. The car will however not continue to run unless I keep giving it gas and it still puts out a profuse amount of grey/tan smoke. I don't think this smoke is due to a coolant/head gasket leak as I've witnessed this before on another car and the smoke is of a different quality. In addition to that my compression is good and consistent between all 6 cylinders. It seems to be a fuel delivery issue. I don't think it is a flower pot thing since the inside of my tank is pristine looking. Another member of this board sent me a personal message suggesting that my WRD might be stuck in the warm position. I'm thinking about going down this path and checking the device.
How does one go about checking the function of this device without disassembling it altogether?
Dimitri
-
Hello,
Try running it for a short time without the radiator cap on. In this way your cooling system will not pressurize. See if the smoke issue goes away temporarily. Rich fuel mixture can also cause smoke. Possibly a stuck injector, stuck intake starting valve. Lastly a ruptured automatic transmission modulator diaphram will cause whitish smoke. Transmission fluid will show up on #6 spark plug also.
It would be a good time to remove all the spark plugs and read them.
-
quote:
Originally posted by dseretakis
Well, it's 3 months later and I've been able to get back to my car. The first thing I did was change out my resistor Bosch plugs with non-resistor NGK ones. This solved a big part of my problem. The car now runs smoothly on all 6 cylinders rather than 3 or 4. The car will however not continue to run unless I keep giving it gas and it still puts out a profuse amount of grey/tan smoke. I don't think this smoke is due to a coolant/head gasket leak as I've witnessed this before on another car and the smoke is of a different quality. In addition to that my compression is good and consistent between all 6 cylinders. It seems to be a fuel delivery issue. I don't think it is a flower pot thing since the inside of my tank is pristine looking. Another member of this board sent me a personal message suggesting that my WRD might be stuck in the warm position. I'm thinking about going down this path and checking the device.
How does one go about checking the function of the WRD device without disassembling it altogether?
Dimitri
Just remove the two screws that hold the thermostat down--the thermostat's the tower that sticks up with the coolant lines going to it. You should feel the thermostat lift lift a little under spring pressure as you loosen the screws. If it doesn't, the piston below is stuck in warm position, then you have to extract it. But first see if it (the piston) moves up and down against the spring. If it does, it's ok.
-
Thanks, I'll try these suggestions. My car is a manual shift so the automatic transmission modulator diaphragm won't apply.
Dimitri
quote:
Originally posted by ja17
Hello,
Try running it for a short time without the radiator cap on. In this way your cooling system will not pressurize. See if the smoke issue goes away temporarily. Rich fuel mixture can also cause smoke. Possibly a stuck injector, stuck intake starting valve. Lastly a ruptured automatic transmission modulator diaphram will cause whitish smoke. Transmission fluid will show up on #6 spark plug also.
It would be a good time to remove all the spark plugs and read them.
-
Thanks, I already removed the whole WRD. I'm waiting for a new thermostat since I question the function of the old one and besides I may of ruined it by accidentally pulling the thrust rod out.
Dimitri
quote:
Originally posted by dsayars
Originally posted by dseretakis
Just remove the two screws that hold the thermostat down--the thermostat's the tower that sticks up with the coolant lines going to it. You should feel the thermostat lift lift a little under spring pressure as you loosen the screws. If it doesn't, the piston below is stuck in warm position, then you have to extract it. But first see if it (the piston) moves up and down against the spring. If it does, it's ok.