Tampa 928s

80 Euro CIS

We have been chasing a rich condition in number two cylinder, changed the injector, tested the wires and finally came to the distributor cap. Got everything back together this morning the car has run the best it has since I started working on it.

This morning I went for a test drive:
I pulled the # 2 plug to look for richness when I got back to make sure, it looked fine. When I went for a drive after checking the plug the car was surging and smelling rich, so I replaced the plug and double checked everything this is not the same symptom I was experiencing before.

When we had the FP gauges hooked up yesterday it would not go below 75 Lb's the test with the **** closed or open the pressure was the same. When we were looking at running the Rpm's up to 2K the FP needle fluctuated wildly back and forth 2"Lb's in either direction.

Today I put the gauges back on and now my control pressure is at 50, something I never have seen before but it is running like crap.
So is the blockage now fixed and the Wur needs adjustment or are there other issues that just came up?

Tampa 928s

Should control pressure change with Rpm:s?

jpitman2

Dont think control should change with load - system might move a bit if the delivery rate isnt up to spec. I wouldnt worry too much about 1-2 psi fluctuations unless there is another symptom. Mine runs system 75 , hot control 45, runs very sweetly, and very good cold starts and driveability.
I would be surprised if it ran with control the same as system - indicates a blocked WUR. When mine was sick control got up to 60psi, and you could gradually get up to about 25mph, but that was it. 50 is probably driveable, but if you have moved the mixture adjuster to richer, you might need to lean it some - try a small amount to lean and if this is the issue, you should get an improvement.
jp 83 Euro S AT 53k

Tampa 928s

Just to go over it again, the car sat for 10-years and the control pressure was always the same a system pressure. I used compressed air on the WUR filter to clear it, not a good idea in hind site. The car perfect for one drive then this surging and popping at idle.
My thought is that I dislodged some blockage into the FD due to the fact that now the pressures are reading correct.

I spoke to Zeus and he has a few tips for me to try tomorrow. Since I did replace the cap yesterday this could be an issue Bosch was not available so it is an aftermarket.
Zeus recommendations:
Electrical
Going to remove one cap lead at a time @ 2k to try to locate the bad cylinder.
Replace old cap

Fuel test
Crack open each fitting at FD look for seepage and a change in idle.
Spray carb cleaner at idle and see if the popping goes away.
To test for fuel issues under load
Take a 10 foot vacuum line connect the red stream nozzle to it by using super glue. When driving squirt the cleaner and see if the surging goes away.

If it turns out to be a blockage in the regulator I guess I do not have a lot of options. What is the best way to clean out the F/D with out taking it apart.
It was suggested to run the motor up to 4K remove the FP relay and the engine vacuum may suck it out if a piece of crap is stuck on the regulator.

Any feedback will be appreciated.

jpitman2

Doubt you can clean a FD without dismantling, but havent had to do mine so far. Dismantle and clean WUR (if not already) - see a doc I wrote at www.landsharkoz.com/images/pdf/wurfix.pdf . Once you have the regulator cover off you can readily blow through the inlet and outlet holes to ensure they are clear. If you can get the inlet brass gauze filters out, they are best cleaned by burning off the debris. One set of these I have comprised FIVE layers....If the O ring inside looks crushed, you might be best advised to get it re-conditioned - see a recent post linking to an ebay seller that does them for a good price.
Locating the misfiring cylinder is very useful - then you can swap things around to try to prove the cause - plug, lead, cap, injector etc. If you remove a plug lead while running, watch out for getting belted - there are warnings that there is enough Volts to do you harm.
jp 83 Euro S AT 53k

Fabio421

Mark, you really need to go back and rewrite your posts so that they can be understood more easily. I was there and I still don't understand half of what you are trying to say.

Is the system pressure 50 or is the control pressure at 50?

karl ruiter

Not totally following what is going on, but if you are looking at the FD there are three things you can do without rebuilding:
1) The input fitting has a 'secret' inlet screen. You can remove this.
2) The control plunger can get gummed up and stick. You can remove the FD, turn it upside down, and spray carb cleaner on the plunger to free it up. You can also remove the control plunger and clean.
3) The system pressure is regulated by a spring assembly that screws in the side and has several O rings. You can clean and replace the O rings.

Tampa 928s

Sorry form the confusion I should of kept it on my old thread:

I pulled all the wires this morning to see which one effected the running. It seems not to change idle when I remove the # 2 lead from the distributor.
The number 2 cylinder was the one that the plug was black since I received the car and have cleaned the plug 3-times.

I have looked at the air gap on the metal rotor inside the distributor all look the same. I did find some oil in the distributor that was pooled near the number 2 wire, cleaned and tested it, still surging.

I am going to order a replacement wire and plug to eliminate this issue. since this has been a problem from the beginning and the car is now acting worse then before.

The reason I am convinced it is a fuel issue is that my control pressure never was less then system pressure. Yesterday morning after the car started running bad I checked the control and system pressure and it is now working correctly. When cold 25 eventually up to about 50 P.S.I which is correct for this car. The only thing I did was to blow air into the WUR inlet to clean out the inlet filter. I believe it may have dislodged some crap after sitting for 10-years.

Looking for an option to removing the fuel distributor, from what I read nothing good happens when you try to rebuild these.

One other thing Shawn and I did was to adjust number two cylinder Fuel distributor feed, it has adjustable pressure controls for each cylinder. When we did not see a change we set it back to the original setting.
Could this be a issue that started this problem?

michael j wright

After cleaning my WUR it did the same thing that you are describing. Seeing as the car started to run bad AFTER your preasures came back into speck, I would assume that you went from a lean to rich condition. You most likley richened the mixture in order to get it to run while you had to much controll preasue- as I did. After cleaning, controll preasure goes down, richness goes up. I would do as jpitman sugests first before you start chasing ghosts.
Mike

gbgastowers

I had a terrible problem with a new to me 82 Euro S. It would not run right and stumbled under load. It had the Mercedes adjustable FD that it sounds like you have and I could not get it adjusted right no matter how much I monkeyed with it. I finally found the correct used FD on ebay and cleaned it up inside and put it on. It was a night and day difference and I would highly recommend ditching the Mercedes FD and finding a correct one for your car. Gunar
link here>https://rennlist.com/forums/928-foru...elp-fixed.html

Tampa 928s

One thing I did not do is adjust anything, the kiss of death it your correcting another problem.
I believe since the Wur pressures are now working correctly it may have sent the crap into the fuel distributor and now causing this problem.
If found this guy on E-bay as a last resort: http://cgi.ebay.com/ebaymotors/ws/eB...TQ:MOTORS:1123

Rich9928p

I highly recommend

CIS Flowtech LLC
Larry Fletcher
19225 County Rd 13
Fairhope, AL 36532
www.cisflowtech.com/
(251) 929-3771

Larry can test your fuel distributor and WUR and let you know if they need a rebuild. He is a top notch guy and has done rebuilds for my '79 CIS cars.

Fabio421

OK, last night I made a house call to Mark's house and we found the source of the surging. That problem is solved. It was just a vacuum line that had gotten disconnected while he was checking the plug after that last test drive.

We still have a problem. The #2 cyl. is not combusting. There is spark going to that cyl. but if you pull the plug wire off of #2 while the engine is running, the engine doesn't lose any RPM and the tone of the engine doesn't change. The #2 plug gets very black and sooty. We know we are getting spark there because we have tested it. We took the wire off and hooked it up to a little tester that allows you to change the gap and watch the spark jump. We increased the gap to more than 3/4" and it still jumped. We tested a couple of other plug wires attached to other locations on the distributor just to compare. We could see no discernable difference in the length that the spark would jump, or in the intensity of the spark. Just for testing purposes we replaced the plug and the wire to #2 but it made no difference.

I'm convinced that we may have too much fuel going to that cylinder. This car has one of those Mercedes Benz style CIS fuel distributors that allows for adjustment of each individual cylinder. How possible would it be that we are getting so much fuel in that one cyl. that it is unable to combust? We changed out the injector on cyl. #2 to see if it made a change. It did not. The next step is to change out the fuel distributor with one of mine to see if it makes a difference. I'd rather avoid that if possible. Any ideas?


Thanks in advance for your help

gbgastowers

I had a terrible problem with a new to me 82 Euro S. It would not run right and stumbled under load. It had the Mercedes adjustable FD that it sounds like you have and I could not get it adjusted right no matter how much I monkeyed with it. I finally found the correct used FD on ebay and cleaned it up inside and put it on. It was a night and day difference and I would highly recommend ditching the Mercedes FD and finding a correct one for your car. Gunar
link here>http://forums.rennlist.com/rennforum...elp-fixed.html

Tampa 928s

Weak spark issue:

I purchased a HEI tester and found the following with a new cap and rotor, non Bosch. This tester provides a load to the ignition system to mimic a plug under load.

I am getting no spark on my tester from the plug wire that goes to the spark plug.
I am getting no spark directly off of the cap.

I AM GETTING spark off of the coil wire.

This says the coil, green wire and ignition module is good due to the fact that the coil is firing on my tester.

It points to the cap or rotor not passing the voltage, I have a new cap and rotor coming from Roger.

Zeus has been coaching me on this and feels that's the issue. Has anyone been through this?