[PK 77 911]

Very difficult problem to diagnose.

Bad stumble between 1000 rpm and 2000 rpm. Very noticable at stop lights/signs. More noticable when warm.

Cleaned injectors, changed fuel Distributor. Adjusted and readjusted timming and fuel mixture. Even my very experienced porsche mechanic is having trouble with this one.

Any sugestions. I feel like i should be offering a reward to the person that solves it.

Thanks for any help