Pontiac Repair: stalling grand prix, camshaft position sensor, crankshaft position sensor

Question
o.k. 2002 grand prix gtp 3800 w/auto.48,000 miles.going down the road car will just shut off.sometimes it restarts and sometimes its stubborn till battery runs down.tried new camshaft position sensor (same problem)mechanic hooked up computer and found nothing.replaced the fuel pump relay in underhood fuse box and thought it was fixed but a week later i m right back where i started.no check engine light,only mod under hood is k&n filter. any clues?  thanks

Answer
Hi
First have you determined what your loosing (Fuel or fire?)
From what you are saying, though,
I would suspect the CRANKshaft position sensor.
Make sure if possible that there is NO fire while spinning over and no start.
I have seen Crank sensors, ignition modules, fuel pumps and catalytic converters cause similar problems.
The cam sensor is used to determine injector pulse timing. It will run without cam sensor, just will turn on Service engine soon light (P0341).
I Hope this helps.
Good Luck
Pawl