1990 audi v8Q stalls when engine is hot

[schroederaudi]

it all started about 2 years ago it was in the summer and i put premium gas in it and drove it home when i got home i shut it off and about an hour later i tryed to start it and i would not start till the engine got cold. later on i figured out it was the premium gas because i put the mid grade in and it quit doing that. but now when the engine is hot and u try to start it it will stall when in park dut if you give it gas it will run till u quit. if you hurry up aand put it in drive real quick it will run perfectly any one have any ideas?

[audiqv8]

There are two sensors Crank position sensor (aka Timing reference sensor) and the rpm sensor. If the engine does not start after it shut down until it has cooled then most likely the crank position sensor needs to be replace. To check the rpm sensor crank the engine when the engine doesn't start and look at the tach, it should jump. No jump then the rpm sensor needs to be replaced. If the engine dies while running the most likely the rpm sensor needs to be replaced.

See the following link for location and more information

AudiWorld Forums: Re: Is'nt the crank sensor used when the engine is running to tell the ecu the timing is right?