W210 E300D Violent missfire

[bazztaxi]

Hi.

I have just been given a 96 E300D for free due to the fact that it has a really bad missfire.

Basically it will start fine but it missfires badly making the whole car judder....the car will drive but acceleration is very very slow. and after running the engine for any amount of time there is a smell of diesel!

Any advice on what to look for first would be very much appreciated!

Thanks

 

[rpe2]

Air in the fuel lines, or a vacuum leak.

 

[Number_Cruncher]

With the engine running, one at a time, loosen the injector pipe coupling nut. That cylinder will then begin to miss, and some diesel will leak out of the joint. When (or if) you find a cylinder where the engine note doesn't change as you loosen the injector pipe, you've found the troublesome cylinder.

If there is one bad cylinder, and you do see diesel leaking when you loosen its pipe, swap the injectors between the bad cylinder and any good cylinder. If the missfire moves with the injector, then, you have a bad injector.

If you get this far, then, I would suggest a compression test is the next thing to do.

 

[Parrot of Doom]

I'm betting a leak around the fuel pump area, or air being drawn in through the pre-filter o-ring.

 

[simon_wall69]

Most likely place for a fuel leak is around the housing by the fuel filter. Crank the engine and you will probably see the diesel coming out. Most likely culprit will be the prefilter o-ring that sits in the housing, you will see a fuel line coming out of the top of it.