Author Topic: Restoration Difficulty Level (Read 946937 times)

paults1 · « **Reply #1525 on:** March 12, 2015, 03:23:37 »

Andy can you view the cylinders with a bore scope throug the spark plug hole to see if there is much carbon build up? When I first started mine the no. 5 cylinder totally misfired. The PO had installed the rebuilt FI pump not at the required 20 degrees. Anyway that caused much carbon build up in all cylinders. It took me months to figure out that the FI pump was installed wrong. This was after I had done the linkage test, electrical etc. The cylinders now look much cleaner after approx. 500 miles using aviation fuel. Of course I also thought the valves were bad, but thank goodness they are ok. I really, as well as, many others enjoy your posts. Good luck my man!!

Paul & Dolly · « **Reply #1526 on:** March 12, 2015, 08:08:30 »

Hi Andy,

Seems strange that you have these problems , on all cylinders, if it was all running ok before your overhaul started.

Before panic , check the compression tester out on another car to make sure it is functioning correctly.

Good luck

Paul

andyburns · « **Reply #1527 on:** March 12, 2015, 23:08:11 »

Hope

This morning I got up and purchased a fresh set of plug. This time I went with slightly hotter NGK BP5ES units. I have read a number of you guys use these instead of the BP6ES plugs. Thought the hotter plug might work in my favor with the over fueling issue.

Put the plugs in and this time decided to set up my old Vane Combustion Analyser. Its out of the arc but still quite effective. Just takes a while after the car start to get an accurate reading.

The car fired on the first click and ran absolutely beautifully. Very very very smooth and hard to believe that I had any sort of issue whatsoever.

To my surprise even when the car was on the cold start cycle with the WRD sucking it little head off at 800 RPM the CO% levels were right down at about 6-6.5 which I believe is perfectly normal. Hopefully this test excludes any issues with the pump. Or could I still be getting normal reading even with the pump to crank timing being out?

I listened very carefully to the WRD air filter (Removed) and audibly heard the sucking reducing right do to almost nothing at normal operating temp. There was still a very very slight movement of air through it which when I blocked with my fingers didn't change the engine note at all. Probably should shut off 100% but at this point I dont think this would be a huge issue. Let me know if I am wrong with that assumption.

The car was going so well I decided to seize the opportunity and take it for a quick run up the road. It went well for the first 1k lap and then stalled while I was turning in a drive. Same problem back again. I managed to push start it. It started ok doing this which might be a clue. Back in the garage after I turned the car off it wouldn't start again.

Pulled one of the plugs and the same dry fouling. Not as much as before and the electrode was brown rather than black. All the fouling was confined to the outer perimeter of the plug and the center ceramic below the electrode.

I decided to check the operation of the plug visibly with it attached to the lead and propped up on the top of the rocker cover touching the linkage for a good earth. The spark seemed quite erratic to me and no where near as 'plump' as I would like so I may be onto something.

I have replaced the points with a pertronix electronic ignition so I have to be suspecting this. Also the lead ends have all been replaced but have metered all of these to exactly 2k each. The leads themselves could also be suspect. I am sure they are what came with the car but feel quite floppy like a silicon lead. I am wondering if these shouldn't be here at all and somehow when heating up are changing resistance. I suppose the electronics in the pertronix could be doing something similar as well, ie heating up and becoming erratic.

The only other possibility is the coil and ballast resistor. I have swapped out the coil twice and the problem remained so think this is unlikely. The ballist resistor has a crack in it but still measures up at 1.2 ohms and is supplying the coil 7.5v when the ignition is on and 9.5v when the start motor is engaged.

Still a bit of mystery to why the plugs are fouling. I really cant afford to keep on buying sets of plugs to diagnose so would dearly love to narrow down this problem now before I screw another set.

If any of you guys have and good ideas about what to do next I would love to here.

Any ideas how I can eaisly either eliminate or pinpoint the electronic ignition module.

Feeling a bit better about it all.

andyburns · « **Reply #1528 on:** March 13, 2015, 04:16:13 »

Have also discovered this afternoon that when the engine is warm both the CSV cold start solenoid and the large Fuel Injection Pump cold start solenoid both have power on them for the entire duration the starter motor is turning. I thought I had read somewhere that these two were controlled by the thermo timer switch and that for an early 230sl the maximum that both these should be engergised for is one second during cranking. Perhaps this is my overfueling and hot starting issue in one. Cranking it more just makes the problem worse?

Anyone got experience with this. I am picking I may have rewired something incorrectly perhaps. I will wait until the car cools down and try it while it is cold. I think I have done this before and seen the one second pulse. Perhaps I have a crook thermo switch or is it possible to get the terminal on backward or something similar.

andyburns · « **Reply #1529 on:** March 13, 2015, 04:34:02 »

It looks like a winner!!!!! Disconnected the block on the timer relay and the car started up instantly. Guess it must have just got jammed open during all the initial load of the engine being cranked. Will pull it all apart and see if I can confirm its the cause and then make some sort of attempt to fix it.

I am still interested to know if in conjunction with the thermo timer switch in the block if the one second pulse is suppose to be reduced to nothing when the car is up to temp. Is the thermo timer switch not really a timer at all and it just provides the relay with a signal if the temp of the block is above a certain level.

Will go out and play some more.

GGR · « **Reply #1530 on:** March 13, 2015, 04:37:57 »

You may have found your problem. Otherwise, while looking both at ignition and fuel issues, the rule is first to sort out the ignition as you may otherwise be messing a perfectly working fuel system when the fault is with the ignition. So make sure your ignition works as it should first. On these cars there is a bypass which is connecting the ignition directly to the battery while cranking. Make sure this is connected properly as otherwise your ignition will be weaker while cranking.

66andBlue · « **Reply #1531 on:** March 13, 2015, 04:55:52 »

Quote from: andyburns on March 13, 2015, 04:16:13

Have also discovered this afternoon that when the engine is warm both the CSV cold start solenoid and the large Fuel Injection Pump cold start solenoid both have power on them for the entire duration the starter motor is turning. I thought I had read somewhere that these two were controlled by the thermo timer switch and that for an early 230sl the maximum that both these should be engergised for is one second during cranking. .....

In the tech manual under "starting aids" there is a table put together by JA17 that indicates that on earl 230SL (versionII) the intakes starting solenoid is open during the entire starting period via thermo switch and relay II. The solenoid on the IP is open for only 1 sec.

Quote from: andyburns on March 12, 2015, 01:11:36

Back to the basics. Compression test with all plugs out and only starter motor assistance today showed all cylinders firing around 115psi. Seems a bit low. Anyone know if I am in a bit of trouble with these figures.

Did you remove the fuse to shut of the pump? Otherwise fuel will be injected and by the time to reach the later cylinders they are all wet and and that has influence on your readings.
But since all 6 are even I would not worry too much.Probably a gauge accuracy problem

andyburns · « **Reply #1532 on:** March 13, 2015, 05:02:09 »

People I have definitely found the issue. The car is running perfectly and I have taken it on it maiden 'proper' drive. I have popped her cherry so to speak

The way it drives now is just so different. Over the moon. Thanks to all of those who have helped me with the engine issue to date.

Off to take the wife for a quick drive.

ricrose · « **Reply #1533 on:** March 13, 2015, 05:29:17 »

Congratulations Andy
I am one of the MANY who regularly read and enjoy your postings and have been on your 'journey' with you. I have had nothing to contribute as I never restored my car, but rather opted for an original car and have only had to do regular maintenance and some cosmetic stuff.
Once again congrats and enjoy...

Richard

GGR · « **Reply #1534 on:** March 13, 2015, 06:29:18 »

Well done!

rutger kohler · « **Reply #1535 on:** March 13, 2015, 07:11:40 »

Hi Andy, great that the car is going and you have found the solution yourself, give yourself a gentle pat on the back in view of your back problem. Really really pleased for you.

cheers

Rodger K

andyburns · « **Reply #1536 on:** March 13, 2015, 07:35:56 »

Thanks guys. Took the family out for dinner to celebrate. Its been a long time since we treated ourselves.

I have already pulled the time relay apart and confirmed the heating element windings have burnt out. Probably due to the extended time spent cranking when the car first fired up.

In any event I think I will replace the internal with some modern equipment that isn't so fragile. Keep everything the same looking from the outside. Am thinking of using a one shot 555 timing chip powering a solid state relay. Also adding in a little trim pot to alter the fuel shot duration and also drill a hole in the casing for a mini led that will illuminate to give a visible indication of the pulse and make sure I never never never make the same mistake twice.

I am still interested in knowing exactly how the thermoswitch in the block works. I am picking it was just providing the heating element on the relay with 12v when the temp was below a predetermined warm up value. Over the value the relay will never be activated.

Tomorrow I am going to pull the thermoswitch and bench test it.

Sleep will come easy tonight! Cant remember the last time I felt this relaxed. Probably the day before I purchased the car.

ja17 · « **Reply #1537 on:** March 13, 2015, 13:01:22 »

Great news Andy!

Congrats and happy motoring!

mmizesko · « **Reply #1538 on:** March 13, 2015, 13:05:47 »

Andy,

Now that she's popped, be careful of others who'll want to drive her.

Congratulations on a job well done, and years of entertainment for us all.

Mike

Peter van Es · « **Reply #1539 on:** March 13, 2015, 13:23:01 »

Well done Andy!

Paul & Dolly · « **Reply #1540 on:** March 13, 2015, 14:55:13 »

Congratulations and well done Andy,

Friday 13th is not always a bad omen.

Paul

Jonny B · « **Reply #1541 on:** March 13, 2015, 15:44:39 »

Andy,

Check on Pagoda Notes, Vol 2 Nos 2 and 3 for a detailed discussion about the thermo time switch.

Scottcorvette · « **Reply #1542 on:** March 13, 2015, 20:02:54 »

Nice work Andy, impressive stuff!

andyburns · « **Reply #1543 on:** March 15, 2015, 20:01:38 »

Thanks everyone for your kind words. I have had the weekend off the car after a very intense week trying to sort that engine issue out. The problem and the solution were both very very simple but as they say everything is easy if you know how. Its so damned obvious now I have kicked myself a few times.

Moving forward yesterday I decided to check my stash of old wiring looms for a second hand timer relay as I had remembered I had wrecked a couple of injected W108's. I was not expecting to find anything as they didn't start making 108's until 67 and the early 230's had an all together different unit that the latter 113 so the production timing I thought would have been working against me. The newer units are 4 pin rather than 3 pins from the earlier units.

To my surprise the first loom I hit had an identical relay. I had marked the loom as an early 250se. Still a big surprise but I was happy to take the win.

Pulled it apart taking careful note of the metal case which did not appear to have any tamper marks. The faulty one I took out of my car had obvious signs in comparison. I tested up perfectly with a nice one second delay. I started comparing it with the faulty one and discovered that the arms on the faulty unit had an obvious bend in them which was preventing the bi metallic strip from opening as early. The previous mechanic had probably not taken the time to look at the adjustment screw about 8mm from the site and gone ahead and made the 'necessary' modifications.

Initially I thought this unit was buggered but after I straightened the arms out the unit operated as expected. I cant explain this as a month ago I tested the system end to end and posted a short video of the csv being energized for about one second. I can now only assume that it was a cold start and I let go of the key the moment it fired which just gave the impression of a one second pulse. Probably the issue has always been present. I never drove the car long enough to take not. Another mistake.

I played around with both of the units for quite some time and got them both running identically. Cleaned up the contact points and double checked. I thought about butchering one of them for a modern electronic equivalent but decided to keep everything old school. I have done this with practically everything else so I may as well not stop.

andyburns · « **Reply #1544 on:** March 17, 2015, 19:00:59 »

Spent all yesterday redoing my hub caps. I cant remember if I blogged about it but the first attempt was a disaster after I used the wrong paint type and also a new gun that I was unfamiliar with. Started from scratch again yesterday and very carefully sanded back the stuff up. 400 grit and then fine scotch. Had to redo some of the masking. Was a bit of a gamble and was not sure if the old masking may have moved or not. Not to worry though as I pulled off the masking tape everything looked as it should with nice crisp edges. A few tiny defects which you could only see if you look at them from a foot away. So a quick polish and on they went. Another thing ticked off. The car is looking complete...ish

I am now debating on if I am going to completely strip the hard top to repaint it. The head lining, wood and internal chrome are all quite beautiful. The only thing that needs a bit of work on the inside is the small rear shelf where the factory mbtex has discolored. I am wondering if I am better off just stripping the external chrome and moldings, paint stripping and painting just the outside. The previous owner has painted the top twice now on top of the original factory color. So its just dripping with layer upon layer of paint that all needs to go.

Today will be working on getting the soft top frame back in the car. When this is done I can set it up and get the side window level adjusted correctly and then get the door cards back on. At this point I have decided to get the car back on the road with registration and a warrant of fitness. To late for the last of the summer drives but I am hoping for a few crisp autumn days.

andyburns · « **Reply #1545 on:** March 18, 2015, 06:18:13 »

Went to work on the soft top frame again today. Decided a few weeks that the old MB Tex covering was just too far gone. Previous owner tried to cover up stains with a nice coat of rattle can material paint. Nice.

Managed to source some material that was very close to the texture of what came off and a color which is almost identical to the headlining of the hardtop. Glued it all up and will trim it back tomorrow when the glue is completely set. Was quite tricky to get it to stretch around all the acute corner and into the hollows. Used the heat gun and worked from the center out to the edges one at a time.

I have also painted up all the clamping plates that are used to secure the soft top material to the frame. All that I need to do now is go through all the screws and source new stainless steel replacement.

Will be quite exciting to get a roof over the old girl but am still a bit nervous about the fitting of the top to the frame. I don't have the constitution to enjoy work I have never done before. Love the comfort zone.

Sorry about the quality of my recent photography. My main 18-55mm lens crapped out a few weeks back and I am now shooting with a 50mm portrait lens which makes closeups very difficult.

andyburns · « **Reply #1546 on:** March 18, 2015, 22:43:02 »

Went in this morning to have another set of MRI's and X Rays and bumped into my spinal surgeon at the hospital. He had turned up to perform an operation on one of his patients in the most splendid car one could imagine a spinal surgeon to drive. A stunning old W109 300sel 6.3 in white. We get on well

GGR · « **Reply #1547 on:** March 19, 2015, 00:30:47 »

Wow! Ask him if he is on the M-100 Group forum and if so what is his pseudo there.

andyburns · « **Reply #1548 on:** March 19, 2015, 02:42:14 »

Will ask him GGR, but I doubt the guy has any spare time given how super busy he always seems. He seems to work seven days.

Came home from my scans and made a start on the soft top. Managed to get my frame back in the car with no damage which is a real bonus. Very awkward shape.

Did an initial fit up of the top. It looks beautiful but once again I have a horrible sick feeling that I have been sold one for a 250/280 where the frame is all steel. The central bow in mine is wood and much thicker than the equivalent steel version in the latter cars. The tails sewn into the hood are suppose to be glued around the bows. All bar the wood one are good as gold with plenty of material. The one for the wood comes up short and aren't even long enough to touch one another. Have no idea what the solution is here. Probably have to unpick the original and sew a new one in. Not what your after when you have spent almost 1000US. I deliberately took the option of buying the most expensive soft top cover so I wouldn't hit this kind of issue.

andyburns · « **Reply #1549 on:** March 19, 2015, 02:57:16 »

Another potential issue is that the early 230s appeared to make use of the thin wire, threaded through the soft top fabric, between the A and B pillar. Looks as if they were used to keep the tension on the top so it wouldn't flap and the glass to soft top junction.

The new top doesn't have the channel sewed into it and has shipped with two lengths of rubber which are glued along the same line. Again I am wondering if I have been sold the wrong top or if the standard replacement for the early 230 version and you simply throw away the wire and run with the rubber strip. Who knows. It would have been very very nice if the top came with a quick one page instruction guide. Even if you handed this over to a professional this sort of stuff could get very confusing and easily get installed incorrectly if you dont know all the subtle differences (which your average trim ship guy wouldn't).

Another potential issue I have also been eyeballing is the thin chrome strip which nails from the outside, through the soft top and into the wood bow. Perhaps I simply cut off the tail and rely just on the nailed trim to hold the top. Or perhaps I should discard the outer trim as putting nails through an otherwise water tight top may not be a wise idea. I have heard that the external chrome trim can scratch up the rear clear plastic when things are all folded down. Would love some advice.

Also not sure if I have made the right choice of color for the new vinyl I have glued to the the soft top frame. It seems a bit arkward between the black leather on the top of the screen and the tan color of the top lining. I am interested in what your car has. Anyone know what the factory did here. I may end up pulling the entire frame out and starting again with this. Big waste of time and money but I really want to get it right.

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Author Topic: Restoration Difficulty Level (Read 946937 times)

ricrose