83 300 Sd

[bbergman]

I just bought an 83 300SD with 290km (kilometers) on it. The car runs good,starting is not a problem but won't idle until it warms up, just stalls when you take your foot off the pedal. I am going to start checking all vac. lines and changing the filters this weekend, also try to get the valves adjusted in the next few weeks. Is there anything else I should be checking or should I adjust the idle speed up a bit? The Banjo bolt seems to be a talked about thing to cleanup as well. I live in the Toronto Canada area and its going to get colder yet.

Thx Brad

My first MB

[gasman]

Check you glow plugs.

[Ken300D]

Typical idle speed should be in the range of 700-750. I'm not quoting from the factory manual so I might be off a bit, but that's approximately the right idle speed for your car.

There is also a device called a "rack dampener pin" on your injection pump. It helps make the car idle smoothly when hot, but it can cause idle problems when cold if not adjusted right.

Use the search function to look for topics on the rack dampener. The replacement part available now is superior to the OEM pin.

Ken300D

[BGill]

i have an 1981 SD with 354000 miles and i have the same problem so what i do is i just keep foot on pedal for a few seconds and then it keeps running i bought the car when it had less than 30000 miles on it and i have noticed that with milage that i have put on it this condition has progressed slowly when i bought it there was nothing happining of this kind but slowly it has come to this point what i been told that the inner mechanism of the IP developes some play in the speed control governor section and as a result it does not respond quick enough to the fule demands of a cold engine at idle. if the problem is too bad what you can do is rig up the idle speed control from a 123 which basically is a cable controlled by a knob that you can reduce the speed after it has warmed up.
hope that helps
bob

[sixto]

Originally posted by bbergman
I am going to start checking all vac. lines ...

Save yourself some time and ignore the vacuum lines. Manifold vacuum means nothing to your car. Basically, there isn't any.

I think your problem lies in lazy glow plugs or poor compression.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

[bbergman]

Thanks for the advice. Looks like I have a lot maintenance to do. The car was not run much for the last couple of months except to pull it in and out of a garage, not good for diesels. Some injector cleaner and a check of the glow plugs and get some highway miles should help. I did that "plug the breather and see how long it runs" test, it ran 7 seconds so sounds like things are not too bad engine wise, some blowby but didn't seem too excessive. Again thanks for the help, I'm sure ther are more questions to come.
Great forum by the way!

Brad