I have a 1993 Audi 90 Quattro. While driving, if I take my foot off the gas pedal to shift, the car's power cuts out when I press the gas pedal back down.

If I'm not going fast enough, the car dies completely. I'm stuck in traffic, cranking and cranking and cranking. After about 90 seconds of turning over...the engine slowly roars back to life. And I have to hold the pedal to the floor and ease off the clutch just to get going again. Lots of smelly fumes coming out of the tailpipe as well. Blue in color.

The inside of my rear muffler is busted....I'm wondering if a blocked exhaust might be causing this problem/

Any ideas? The problem happens almost daily now.

 

I'd look at the idle valve stabilizer first. When they get gummed up it throws off the idle so much that it'll cut out. As you said, it will still run when you're pushing the gas 'normally'. You can actually take this part off and clean it. It might do the trick. I had a similar problem with my 80.

 

i had a similar problem when my valve got jammed, i pushed up more than normal.