Hi,

I have a small but annoying problem with my m103 in my W124C; when the engine is cold I can only start the engine when I press the accelerator pedal until it "activates" the kickdown. Then the engine starts badly but it starts; it needs a minute or so until I can select a drive position; when I do it right after the start the engine slowly shuts off and can't barely start it again. Right after the start the rpm is at 600rpm; when I wait a minute it raises up to 900/1000; that's the moment when I can select a drive position and just drive. There is no blue or white exhaust noticable.



I checked the coldstart valve, replaced the relay that prevents overvoltage (OVP) with a new one and also replaced the fuelpump relay with a used one. There was no sign that the fuel pump relay was damaged as I could hear the fuel pump when I turn on the ignition and it just sounds good and normal but as it's a common problem I replaced it.

Some dude told me to clean the idle valve which is located near the induction elbow and flow divider. There was a lot dirt in it; I put 12V on it and it made a gentle buzzing noise; I put my fingers on both sides and couldn't feel anything but to be honest I don't know how this part works at all . When I turn the ignition on it's buzzing for about 30 seconds and then shuts off...dunno if that's the expected behaviour. I expected it to be like a fan...it obviously isn't a fan.



When the engine is warm, after several miles, it starts immediately but shuts off slowly just like in the morning;



I always have to wait a minute or so after a successful start until I can select a drive position no matter if the engine is warm or cold. Steering the wheel also influences the rpm a bit but that should be normal.
The engine doesn't shut off in P and N.


What I checked:

- cold start valve
- OVP (it's brand new with two fuses now)
- fuel pump relay
- idle valve
- filter


Today morning I hardly could start the engine as it was a bit cooler than the last weeks and I got blue exhaust after a long try to start it (poor starter and battery).

I just own this car for a few weeks and simply don't know the details of the car; the pre-owner said he replaced all spark plugs, cables and distributor. The distributor cap has a small crack but that shouldn't be a problem, right?

Any help is appreciated.

Kind regards,
Andreas.