intermittent starting problem: crank position sensor or fuel pump? on 1994 Buick Park Avenue

every once in a while my buick won't start. it will crank like crazy but not start. mechanic has narrowed it down to most likely either a crank position sensor or failing fuel pump. I don't think it's ever happened when the car was cold, it usually happens after it's been running for a while and i run into a store or something. after a few minutes of sitting there, the car will fire right up. car runs fine, no stalling, runs strong. any thoughts on which one it could be? thanks for any help.

by in Philadelphia, PA on November 07, 2010
Get Your Car Fixed at a RepairPal Certified Shop.
We certify shops based on expertise, quality work, and verified customer reviews
2 answers 2 comments
ANSWER by , December 24, 2011
Get the driveability test and that will rule out CPS sensor and pigtail. Also, fuel pump regulator filter may be corroded .....clean and reconnect. Crank sensor maybe bad and not working at 100%. Check 3rd cylinder.....could be missing and not delivering any spark. What is your fuel pressure while idilying, and revving?
COMMENT by , January 10, 2012
i have the same problem so far if i shift to low gear and back to neutral it starts every time , mine is just starting to act up, it had done it 3 times over the last 2 months
ANSWER by , November 07, 2010
If you could get some one to listen back at the tank and just cycle the key on and see if you can here the pump come on,You could take off the gas cap and carefully put a hose in the filler neck and listen for the pump.It should come on for a few seconds and then shut off till you cycle the key again or crank the engine.Crank ssnsors are also common on these motors,a scope or scan tool watching for RPM would help.Crank sensor should throw a code and engine light,the fuel pump will not.
COMMENT by , November 07, 2010
Thanks. I took it to a mechanic who scanned for codes and found none. I have the money to invest in replacing these parts, I was just wondering which one is more likely. Also, the mechanic had replaced the fuel lines and the fuel filter. The fuel line was rusted and the fuel filter was clogged. Makes me think the fuel pump is also bad.