YannickF

HI

I have an ABH 4.2L V8 in my Audi 100 and the engine often hesitate (with vibrations) to accelerate between 1000 and 2000 rpm (approx)
Some times, the acceleration is perfect.
I have tried to disconnect some sensor (O2, knock sensors, MAF, Idle valve etc...) but the problem persists.

It seems to be better with the O2 sensor disconnected but I'm not really sure.

I have changed injectors and fuel pressure regulator (I have a seconde engine for parts) without any success.
Air Filter (a cleanable) and Spark plugs are new ones.
I've changed timing belt a few weeks ago..

What do you thing of my problem ?
Thanks

MP4.2+6.0

Look for vacuum leak in the hoses as a guess

YannickF

Hi

thanks for your answer but which hoses are you talking about ?

meatwad/beefcake

caps, rotors, wires, etc....

brittcrowell

<ul><li><a href="http://www.brittcrowell.com/2006/2006-02-08_Working_on_the_A8/">http://www.brittcrowell.com/2006/2006-02-08_Working_on_the_A8/</a</li></ul>