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· Registered
2 Posts
Discussion Starter · #1 ·

i try to describe the problem of my car, 1999 octavia 1.9 tdi AHF engine, maybe somebody can help me, my mechanic can't.
when i start the car in some points between 1k to 2k rpm i heard some noise from engine associated with a lot of black smoke. when this happens the rpm don't increase. after a few moments rpm is back to normal and the noise and the smoke disappear. In about two minutes after start the car run just fine. Rarely the problem appear during trip and just in low rpms.

robert benedek

· Premium Member
23,904 Posts
I had a similar problem, a boost hose popped off due to a weak clip and the engine smoked heavily, shook, and wouldn't go past a low rpm. Your case is different because it starts and runs fine later and a boost hose doesn't go back in by itself.

Some guesses: something about cold start is causing either too much fuel or the injection pump to give too much fuel or at the wrong time.

It could be a problem with the MAF sensor or other air related problem but the smoke and rpm problem, and the fact that it runs fine after 2 minutes makes it sound like a fuel problem.

Some things to check: cold start advance valve on fuel pump, case relief valve on fuel pump, 3rd injector sensor and wiring. Also check the wiring to the fuel injection pump, it could be rubbing somewhere. Monitor the fuel injection quantity during a cold start vs. 2 minutes later when it's running fine. Here are details on how to do that: http://www.myturbodiesel.com/1000q_how_to/multi/IQadjusthammermod.htm
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