Last year the car would not start one Morning?

DEEDEE-1

MEMBER
2001 PONTIAC GRAND AM

Last year the car would not start one morning. It would spit a little while turning, just to tease us. We towed it to the local garage, they called next day and said it started right up when they jumped it and can't find any "codes". Worked fine for nearly a year then did it again. We tried various things without success. Next day when we were hooking up to tow it we decided to try one more time-noticed we had left the key on overnight. It started right up when jumped. One month later it quit again. We have tried leaving the key on overnight (re-setting computer?) But still no luck. Any ideas? PS after 1st reply: this is not a battery issue or charging problem.

1 Reply

SQM

MECHANIC
6,383 POSTS

Hello,

It sounds like you have a sensor that intermittently fails to provide signal for the engine to start.
It could be a crank position sensor. As you are mentioning it is started to have the issue more often then before. Typically some of these sensor might fault ones is a great while but as the time passes the issue becomes more common.
The crank sensor is located right next to the oil filter housing (see diagram).
Heat and vibration can overtime make the crank sensor produce wrong signal to the ECU. In return the engine will not start even with a good battery or starter.

You might find these articles helpful:

https://www.2carpros.com/articles/how-a-crank-shaft-angle-sensor-works
https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor
https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

Another possibility is a faulty coolant temperature sensor. That sensor can also send wrong signal to the ECU, it could fault out and send a signal that the engine is 'too hot' to start.

I have attached diagrams for your reference.

Please let me know of any questions.

Thank you.

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