The car starts fine but after the initial "warm up stage" where the idle is at 1k rpm, it'll drop to 600-700 and start running really really bad. Some smoke, almost turns off.

But, if i press the brakes or pump the brakes the rpm goes back up and it starts to idle like their is no problem for a few seconds then it goes back to crap.

I think it might be a vacum leak somewhere and i was gonna start with the EGR. Anyone got some advice?

1995 stock motor lt1 a4

 

Just start poking your ear around and listen for a whistling or sucking sound.

 

definite vacuum leak somewhere

 

i had about the same problem with mine a few years ago. I found that i had no vacuum leak, but the voltage to my pcm was about 1V off. itook it out, cleaned off the connectors with alcohol, and after reinstalling it, my voltage was back to normal, and i didnt have a problem with the engine about dying on me

 

I'd check the IAS too, make sure it is working and not fouled up.

Can you scan it and see what the PCM is telling the IAS to do?

 

Can't really hear anything.



How do I check the voltage of the PCM?


Where is teh IAS located?

 

600-700rpm would be within the specs for the A4 in neutral. But is that read off the stock tach (100-200 higher than actual) or off a scanner?

Sounds to me more like its running too rich, if it actually smokes under those conditions. Pumping the brakes may be allowing air to enter the vacuum system and leaning the overly rich idle condition.