Engine runs "eye watering rich"...links and csv ok

[Allen F]

Hi Folks,

I have a 66 230SL which runs really rich.  I got some guidance from the group last spring, and ran through the adjustments on the linkages (thanks to all for that post) and everything seems ok.  The throttle opens just slightly ahead of the pump arm, but I can't imagine it would make that much difference?   The CSV seems tight without leaks.  Any other reason this thing might be guzzling?  It runs excellent otherwise.  I am getting about 9mpg, down from about 16 prior to the engine rebuild.  I don't mind getting poor gas mileage, but I feel bad for anyone who has to drive behind me.  Their eyes will be watering and probably pass out.

Thanks for any tips in advance.  

Allen Frechette

[merrill]

have you done a richness test?

at idle, disconnect the cross linkage at the injection pump linkage
push open the injection pump linkage

let us know

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[Shvegel]

Assuming you didn't change any pump settings when you rebuilt the engine have you rechecked the ignition timing and dwell? Especially if you are experiencing any backfiring.

[jameshoward]

Allen,

I also have a '66 230SL that...runs rich. Not a rare thing as a search thru the site will show.

As part of the process of chasing this down and getting the car sorted having got it, and I'm not there yet, I checked the oil level on the FI pump. There is a little dipstick at the rear of the pump with a nut that has a lug on each side to allow for its removal by hand. When I checked the level first, the oil flowed freely from the pump out of the dipstick hole. It had far more in it that it was supposed to and I'm in the process of getting that problem addressed. When I replaced the oil with the correct amount (about 250ml) I noticed a significant improvement in running and, I am pretty sure, MPG.

You could check you pump oil level and see if it's OK. Hopefully it won't chuck oil all over your floor like mine did.

JH

[J. Huber]

Hi Allen, what are your cold and warm idle numbers (RPMs) like? Auto or stick?

James
63 230SL

[jameshoward]

James,

For comparison for when Allen posts his figures, my car just won't idle at warm up without my foot on the gas (probably first 2 mins), but when warm idles away quite happily about about 650, which seems low but there she sits without a hiccup.

What do you think?

JH

[J. Huber]

Hi James. I am by no means an expert but your idle strikes me pretty darn low. Did you set things when the engine was still cool? I'd be inclined to get the cold idle at least to where it would stay fairly steady by itself. It may rise a bit when warm but should still be ok.

Mine on the other hand is a little on the higher than normal side. And I think this is why I am rich and mpg is a bit low (12-15). On dead cold start -- car starts up with no throttle at about 825-850. It oscilates slightly but will idle to a steady warm. When warm, I actually have three steady idles: at start-up after a stop it stays at 900; in gear it finds 800; and after being in gear upon return to park it set at 950! Like I said, I know its high but generally the car seems happy.

James
63 230SL

[hands_aus]

there are many components in the cold start sytem.
relays
solenoids
CSV
injection pump thermostat
free movement of the WRD
free movement of the injection pump rack
linkage adjustments
linkage rod looseness
inj pump air filter
correct adjustment of the throttle valve position.
correct adjustment of the idle switch on the inlet manifold.
oil level in the reservoir of the 230sl Inj pump
air filter

You need to make sure all of the components are adjusted correctly


Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[Allen F]

Hi Folks,

Thanks for the tips.   It's an automatic, and the CSV did appear to be leaking.  I resurfaced the orifice using heavy duty rubbing compound, and cleaned it and it test ok now.  It still seems rich though. All of the linkages are really loose, but odly the car always ran well, even before the rebuild, even with loose linkages.

I will go through all of the "lowest hanging fruit" and report my findings. I disconnected the pump linkage at idle, but I am not sure what was supposed to happen?  

Allen

Allen

[J. Huber]

Hey Allen. I recently replaced my ball sockets and the bushings on the main linkage section. Not difficult or expensive and it makes a nice difference. Do a search here and you will find much good info.

James
63 230SL

[rwmastel]

quote:Originally posted by Allen F

I disconnected the pump linkage at idle, but I am not sure what was supposed to happen?

Allen,

Hi.  Here is a great thread on some fuel injection linkage info.
http://index.php?topic=5003

Disconnecting the linkage rod that crosses the valve cover allows one to test for fuel richness as the car idles.  Push on the fuel injector pump linkage to add fuel and note any change in idle.  Push on the venturi intake linkage to add air and note any change in idle.  Doing this one test at a time allows you to figure out what is needed to make the car properly more lean or rich as needed.  The goal is to have the idle drop RPM when making any manual adjustment.  Once there, then true idle RPM adjustments should be made with the idle air screw on the intake manifold.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[TheEngineer]

Allen: These cars don't measure air density but the fuel/air ratio is fully adjustable. But beware: If you adjust too lean the combustion becomes hotter. You can expect about 17 MPG average if you drive easy. If you push the car your milage will drop substantially. You should also check the setting of the altitude compensator. If it is defective you'll run rich. How do the plugs look? Make a medium speed run, pull over, take one plug out.I'm using regular and get 17MPG

'69 280SL,Signal Red,Automatic,retired engineer, West-Seattle,WA

[Cees Klumper]

In a separate thread, I asked some tips for getting the linkages set up so that the air intake flap opens up all the way at the same moment that the FI pump is at its max position. I fiddled with the lengths of the three relevant linkage rods until I almost (not quite - I ran out of adjustment on the rods) got it there. It made the car drive very smooth. Also, though, I noticed that the exhaust smell was a lot stronger than it had been before. Then I noticed that the gas mileage had deteriorated enormously! So tonite I decided to pull a spark plug: it was black with soot, when in the past they were always nice and gray, like all the books say they should be.

So I re-set the rod lengths, starting with the one that goes to the intake flap: making sure it lines up with the small hole in the bracket that holds it in place. Next rod to adjust was the one going to the FI pump, and the last one the short one going to the gas pedal linkage, in between the exhaust manifold. Then I filled up the gas tank and took it for a spirited drive. There was no discernable difference in the way that it drives, however that nasty exhaust smell is all gone. I bet it is back on its normal MPG behavior as well.

I noticed once before how very sensitive these cars are to just how these linkages are set up, and this to me is another reminder. I would not be surprised if poor linkage adjustment, or the condition of the linkage points themselves, accounts for a lot of poor running conditions, poor mileage etc.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[merrill]

cees,
so, my 66 pings and I stink of burnt fuel after driving it.

from your experience in the post below, when you re adjusted the linkages what changed?  more air? less air?

I think I need to lengthen my throttle body linkage a little, of course after verifying the tb set up

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[Desertpagoda]

Sounds and smells very familiar...have the injection pump rebuilt. You can adjust 'til the cows come home. Time for an overhaul of the pump. Call Gus at Pacific Fuel Inj.in S.F. if you dont know someone closer. $$$ But it will make the difference! k

[thelews]

quote:Originally posted by Desertpagoda

Sounds and smells very familiar...have the injection pump rebuilt. You can adjust 'til the cows come home. Time for an overhaul of the pump. Call Gus at Pacific Fuel Inj.in S.F. if you dont know someone closer. $$$ But it will make the difference! k

www.blackforestllc.com will also rebuild pumps separately.  They're very good.  No affiliation other than they're rebuilding my 190 SL engine.


John
1967 Early 250 SL Red/Caviar, Manual

[psmith]

My car ran that way too.  To the point where I had someone pass me holding their nose in the international P-U sign.  I had taken the linkage off for restoration, and even though I measured each link carefully, I guess I didn't get it quite right.  I took it to a pro, and now it runs great. Also, as James Howard said, the 230 pumps have their own oil supply and should be checked and changed.

John, is that your 190 engine?  The picture looks kind of funny, or maybe they just have a really deep oil pan???

Pete S.

[thelews]

quote:Originally posted by psmith


John, is that your 190 engine?  The picture looks kind of funny, or maybe they just have a really deep oil pan???

Pete S.

Yes, that is my 121 engine (190 SL) that www.blackforestllc.com is rebuilding, now assembling.  Yes, they have a much deeper oil pan than the 113.



John
1967 Early 250 SL Red/Caviar, Manual

[merrill]

Guys,
thanks for the reply, but everything is rebuilt, motor, inj pump, csv, fuel pump, new hoses and lines, radiator, alt, thermostat, coil, points, condenser, etc ect ....

The car runs great wide open, I just need to fine tune the linkages.
At lower pedal position it pings a little so I think I need to lengthen the throttle body linkage just a tad.

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[jameshoward]

Matt,

I had my FI pump rebuilt a few months ago. When I got it back the car just wouldn't run properly. It too was OK wide open, but at idle it was all over the place, revving up and down and nearly stalling. I ended up enriching the mixture by 15 turns on the FI pump and balancing out the air using the idle mixture screw. I went through Joe's linkage tour three times, checking everything. On teh third time, I all came together perfectly. And I mean PERFECTLY. I'd just been doing things incorrectly, or hadn't been careful enough. I started with valve clearances, then through dwell, to timing, to linkage, etc etc and it just came right. Do the lean/rich test and see what happens. I found out that the guy who had rebuilt my pump had seriously leaned out the mix (which is what I'd asked him to do). By lengthening the linkage rod to the FI pump I created the condition where the pump ran rich. Doing that small test made the car run much better. I then set about using the idle mixture screw at the back of the pump and adjusting the linkage etc to find the sweet spot. I'd suggest you stick with it.

JH

[merrill]

JH
thanks for the reply, while trying to figure this out, i pulled the pump for the second time and sent it back to hans to verify.

anyway, he checked it out, re set everything and sent it back.

I believe  I need to go thru the linkage tour again.

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230