1991 Pontiac Grand Prix GTP

Asked by Jan 12, 2011 at 03:10 PM about the 1991 Pontiac Grand Prix 2 Dr GT Coupe

Question type: Maintenance & Repair

I can't get the car started, It all started when after the car sitting for just short of a year I went out (freezing cold) and plugged in the car, installed the battery and after a couple hours started the car drove it 15 kms, stopped and got fuel started the car up and drove another 35kms, with no problems, then I let the car sit for 3 days unplugged in the extreme cold, went to try to start it with no success so I plugged the car back in for a couple of hours boosted the car (started it) pulled it into the driveway left it idling to warm up and approx 10 minutes later the car stalled and won't start again. So I've tried everything, checked all the fuses, installed a new crank sensor, new modulator, new coils, new fuel filter, did all the tests on a top of the line scanner everything reads fine, did the fuel injectors test they are opening and closing, tested spark everywhere and have spark, have fuel from pump, even checked the timing belt and it's all lined up perfectly. I'm at my wits end. Is there something I've missed?
Any idea's would be welcome.
Scratching my head Greg

7 Answers


I believe it has to do with the fact that its been sitting for so long. one day out of a year isn't going to help it. Pardon me if I may be rude, but the car should have been started once a week through the spring, summer and fall, and once a day in the winter. Leaving a car sit isn't good for it at all


have you got spark? how about fuel pressure at the engine

Yes as matter of fact it seems there is spark and fuel pressure 45p.s.i. also a crank reading and injector bulbs lighting. We are now looking at a sensor that apparantly restricts fuel to the injectors if the computer thinks it's the vehicle is flooding. Not exactly sure if this sensor even exsists on this vehicle as of yet. If you have any ideas on this fuel restrictor sensor, what it's called? does it exsist? Or is it just the computer alone on this particular vehicle that controls the fuel? Thanks for the response. Still scratching my head, Greg


Dirty fuel or to much water from sitting so long. Could also be engine seized up partially could need some lucus to clean up engine

1 of 1 people found this helpful.

Thanks judson, i don't think it is water in the tank I had started the car a few times and even drove around the block a couple of times. Then a couple days later I started it went and put in fresh fuel then drove over 40 kms, and parked it. After that, it got super cold and I left the car parked, when I went to start it I had to plug it in and boost it to get it going it was still freezing out but it started and ran fine. I backed it out of the stall and left it in park idleing and appox 5 minutes or so idleing it just stalled (died) and would not start again, turns over like crazy, lots of spark, and fuel, did all the tests you could imagine, and just won't go. The only thing I have yet to change is the brain box (computer) That's my next step, done everything else. So judson if you know anyone with a computer or computers would'nt mind a back up for a 1991 Pontiac Grand Prix GTP 6 cyl, dual quad overhead cams send them my way. Thanks for your reply; gregsandy

engine computer has nothing to do with initial starting of car. it is controlled by the icm- the ignition control module.Computer takes over after motor hits 400 rpm and holds there for a few minutes.


If you have access to a scanner,try looking at the Engine Coolant Temp sensor.E.C.T if this is not reading correctly it will cause a no start or hard start,also check Mass Air flow,you did not mention any check engine lights on,also scan for codes,particularly history codes let me know what you find out.drdc

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