I have a 1985 300td. It starts easy even cold, uses about 1qt of oil per 3,000 miles, so I think that the motor is in pretty good shape. I have noticed, however, that when I accelerate hard, there is very little smoke until about 4,000 rpm and then it starts to smoke black smoke pretty well. It looks like I'm james bond putting down a smoke screen. This is the only time It smokes. I'm thinking it's getting too much fuel, but it may be running out of boost at that RPM and over fueling? it's putting out about 9psi of boost.

Any thoughts. I got flipped off yesterday because of the cloud and want to know if I minimize it.

thanks
jason