'83 300D | no smoke, no power, until hot
 

Hi All - n00b to this forum.

Recently picked up an '83 300D w/ 250k miles from a little old lady that had neglected it for 5 years. On the first drive home, it would literally take 5 mins to get up to 50 mph, and that's where it topped out.

Following a diesel purge, some sea foam, and a change out of both fuel filters, I got decent power and speed back, but the previously smoke-free car poured black smoke - I'm talking people-giving-me-the-finger-at-stop-lights smoking.

Last weekend I changed the timing chain, rebuilt the injectors w/ new nozzles, valve adjustment, changed out all my belts, oil/filter, air filter, and did a full transmission flush.

At first, all was good, outside of disappointing acceleration when the vehicle was cold, and crazy conservative shifting at 1200-1400 rpm. 5 mins in, I get the car up to 60, and all of a sudden I have boost and power, and the car is running great. I also start dumping a ****load of black smoke again. The car remains peppy, and boost comes back at lower speeds/gears as well. I stop for a few mins, while idling, and eventually the car stops smoking and I go from a rough idle to smooth idle.

This trend has continued, cold car, smooth idle and engine operation, no power, no boost, no smoke. Get the car hot, the car has great power, you can feel the boost, and you can clear out an intersection with the black smoke.

Most comments I've seen make it sound like low power/boost is typical while cold. But most people seem to see smoke go away (not come), when the vehicle is hot.

Given the power and smoke, it seems like I have too much fuel (or not enough air) when hot. Does this sound like a pre-combustion chamber issue, ALDA, a turbo issue (haven't purchased a boost gauge yet), or other?

I'd start with the ALDA sensing lines. There are banjo bolts that get clogged with soot and a switchover valve on the firewall that can also become clogged.

Find out what kind of turbo you have, it'll be a Garrett (AiResearch) or a KKK. If you have a Garrett, it'll have a boost sensing line to the waste gate actuator that could be rotten.

When you rebuilt your injectors, how did you do it? Did you pop test any of them? If not, you could have one or more hanging up and dumping fuel.

Thanks. Will check out the sensing lines.

For the injector rebuilds, I removed all injectors, disassembled, soaked in brake cleaner for 6 hours, cleaned with a wire brush, installed new nozzles, then reinstalled. No pop test. What causes the hanging up and dumping of fuel?