my moms 95 bonneville will randomly not start. my dad is a mechanic and has already replaced the ICM and checked the basics but we're unsure of y it is randomly not starting. it tends to not start after a short time of about 10min to an hr. but thats not always true. its very confusing and not sure where to go. my dad thinks it could be the crank sensor or cam sensor but we dont just wanna throw parts at it. any suggestions would be great!

OK, first let'* find out which system is causing the nonstart. When this happens do you have spark? If you do then it'* most likely the fuel system. If that'* the case check fuel pressure, are the injectors working? If you don't have spark we can look at that area closer.

when it does not start there is NO spark but the fuel pump turns on.

Have you checked the coils? Does the happen when the car is hot or cold?

well the coils should all be good all 3 would have to be bad. it happens when its both hot and cold. its usually a short trip. we could be gone to the gas station and turn the car off and it wont start back up until waiting 45min then it would start again. also could be gone to the store for an hr come out and it would not start. one once has it died while driving. luckily it was in a parking lot going slow.

Sounds like a sensor giving problems. Billboost should be able to help with this.

aight thanks ya my dad was thinkin either the cam or crank sensor.

I've seen crank sensors cause odd stalling and occasional non-starting. Being a 95 though you have the 94/95 pcm which is known to be flaky at best. I would be tossing a coin on changing the crank sensor or pcm. Both could be causing the problem.

picked up a crank sensor just wondering if the harmonic balancer needs to come off and whats the best way to get at the crank sensor to replace it?

UPDATE:

got some codes to pop up:
P0321 (IGNSYS problem, 18X interrupts lost signal)
P0705 (PRNDL switch failure)

never got the crank sensor replaced yet so just curious what these codes mean