2001 Chevrolet Impala 3800 Problem: My car stops when running as if the key were switched off. I can bring the car to a halt, put in Park and start up immediately - no hesitation or delay. There is no obvious connection to the problem. It stops when cold or hot - in motion or idling - sometimes it fails to fail (like the almost three days it was with the mechanic). There are NO error codes or Check Engine lights. The Ignition Control Module has been changed with no luck in solving the problem. A container of gastreatment was added after the first time this happened, so it isn't bad gas. It doesn't appear (to me)to be the fuel pump of fuel filter since it starts back up right away. The car has aprox 122,000 miles on it and I'm the original owner and have not had a problem like this before. Any knowledgable assistance would be appreciated by both my technician and myself - especially me since I'm stuck without my car. Thanks in advance for your assistance.[/align]

 

Most likely it is the fuel pump. This type of problem is not uncommon, but at some point it will get worse and or just die on you and not pump any more fuel.

Personal experience.

 

Sounds like it may be a crank position sensor