I don't know if anyone remembers, but I have been fighting an excessive smoke problem on my 1983 300D every since I got it months ago. After trying many other things, it turns out that the injection pump timing was too far advanced. I believe this was done by the previous owner or his mechanic.

I had excessive smoke at idle, especially with the A/C on, and when you would stomp the throttle you would get a pretty good stream of black smoke. Now all of that is gone.

I'm not quit sure of the physics involved, but somehow injecting the fuel too early doesn't allow it to burn completely. I believe it was PSFRED that said smoke at idle is too early and smoke at high speed is too late. He was correct. In additon, with the IP timing too far advanced, you get a lot of engine noise at idle. It quieted down when the timing was corrected. It runs great now.

Joe

Did you to this yourself?
If so, can you explain (in detail) how it is done?

Thanks in advance.

__________________
Current: '91 300TE 4MATIC 317k and climbing...
Former:
'81 300TD Wagon 168K "Tank"
'83 240D 216K 4spd manual "Da Bear" (aka best car ever)

"Never sweat the petty things...
and never pet the sweaty things."

Yes, I adjusted the IP timing using the drip method. As far as I know, there are 3 or 4 ways to do this job, depending on the IP you have. I first tried to use the method where you looking in the top of the IP pipe and look for fuel to start to well up (sometimes called the Baylor method) but couldn't get it to work.

The drip method is outlined in the haynes manual, or the mercedes manuals (or CD). Do a search on drip tube injection pump timing and you should find plenty of info. The other 2 methods (1 - using a lock pin on later 300D model, 2 - the $250 electronic box method again on later model 300D) can be found in the archieves of www.mbz.org.

Good luck

Joe