1987 560 SEL Hard start, electric?

[American28]

Hi,

I sure hope someone can help.

About 1.5 months ago my 1987 560 SEL began having problems starting. When I go to start it and it starts regularly it will start in 1 -2 seconds. One out of 8 times it wont start in any weather, warm engine or cold, etc. It seems to just do this whenever. The engine will turn over fine but I will get no starting response at all, not coughing or anything else as if the engine is not getting any gas. If I push the accelerator down to the floor the engine will start to catch and sound bad but at least begin to start. It will sputter, cough run but then will even out and most of the time, then run right. Sometimes it will act as if the timing is terribly off and idle horribly then I increase accelerator and it will rev up as if, again, the timing is way off or it is very,very flooded.

I have checked the wires, rotor, etc and all seem fine. It sure seems to me that there is some electrical circuit that either throws the timing off, stops the fuel from coming in or whatever. Also, at times the engine ( when it is started and running fine) will just , by itself, begin to idle high and sometimes smoke slightly. I dont knowe if that is related as this seems to have just started recently.

I am not a "real" mechanic but have worked on my own cars all my life. I have just recently began to work on my Mercedes. If someone could help I sure would appreciate it.

Thanks!

Lance

[xsohaib]

I have 100% the same problem except now my car doesn't start at all and it was towed and put in my garage. If you find the answer please let me know at xsohaib@hotmail.com I have thus far changed the fuel check valve, and the fuel filter. I am gonna check the Over voltage protection relay and the Fuel pump relay next. If that does not work then I am gonna go for the fuel accumulator, or fuel injector and eventually if nothing works pay somebody $450 to JUST diagnose the car.
But being a student I am a bit stretched for cash. BTW I have a 420SEL.

Hope this helps
Sohaib

[Kebowers]

when it reduses to start, does it pump out black smoke when it does go? It sounds like it is badly flooded. A leaking 'cold start' valve can dribble a lot of fuel into the intake when it sits, and voila!! you have a flooded engine.

If the fuel distributor was leaking, it would do it all the time, not just evey now and then. I suspect the cold start injector. Check it by removing it from the manifold. and then activating the fuel pump to see if it dribbles at all.

[American28]

Thanks alot for trying to help me. Yes it smokes but I would say it does not pour out. It will smoke and in fact have an almost sweet smell to it. Not the regular gas/flooded smell that I am used to from american cars - its kind of weird . Could you please zero me in on the cold start valve, where is it, whats it attached to.

Also I have open the air intake area, under the air filter and have seen it look almost wet at times, I assume that is not right and also sounds like what you are talking about. Sounds like the high idle at times I was talking about on the initial post could be attributed to that too. Does it make sense to you that pushing down the accelerator would help it start under the flooded condition?

Thanks again! I really appreciate it.

Lance

[tower]

When you say:

"Also, at times the engine ( when it is started and running fine) will just , by itself, begin to idle high and sometimes smoke slightly"

is the exhaust white (as in steam)?

and adding the sweet smell....I would say head gasket....