1987 Mercedes 300 3.0 L OM603 turbodiesel general questions
 

Hey everyone, I recently won an '87 mercedes 300D on ebay, engine runs well, solig extirior and very nice, if a bit sun-damaged interior. It drives very well but it has a lot of "personality". Starting is finiky, the big fuel solenoid (the one with the "STOP" leaver on it) is somewhat uncooperative. Some times when I turn the key to start it the buzzer wines as normal and it fires up without a fuss. Other times though it cranks well (starter was replaced, new battery" it gets no fuel. Upon inspection of the engine itself you can see that the stop lever is still parked at the bottom of its travel. Playing with the ignition in the car, cutting the accesory power on and off repeatedly, will usually slowly raise it so that it will let fuel in. On rare occasion, no amount of coaxing will get it to lift and I have to pop the hood and prop it up manually to start it. Once it is running I can pull out whatever is holding it up and it stays in place. I assume that whole little solenoid can be swapped out. Is that hard to aquire? Thanks for your input.

You'd get a better reply in the Diesel section.

FYI - I love my 603. :)

woops, thanks mate, stumbled upon this forum via google, foolishly didn't take the time to acquaint myself with its organization before posting willy-nilly

One of the mods will move it over there on Thursday so no worries.

In the mean time you might want to do a search on the "603 vacuum shutoff solenoid" at the rear of the IP and test to see if it is leaking.

It's shut off with vacuum, the ignition switch vents the vacuum in the run position to turn the fuel back on. You might have a clog somewhere in the vacuum lines. Try pulling the vacuum line from the shutoff and see if it rises quickly to eliminate the shutoff itself.

Sounds more like a bad key switch than bad actuator.

If you see oil in the vacuum lines, it could mean a bad vacuum pump.

If the brass plate in front of the vacuum pump has no exposed screw heads, check the archives for possible failure modes... or take my word for it that it's a poor design. Ideally there will be four exposed screw heads to indicate a resigned pump.

Sixto
87 300D