1999 Pontiac Grand Prix Misfire and Stalling

Problem with my 1999 Pontiac Grand Prix
Replaced spark plugs and wires.
My engine misses and stalls at stop signs, and sometimes runs normally then misses again.

Answer: Well, this could be many things. Could be a fuel pressure pressure problem. Low pressure caused by a plugged fuel filter or failing pump.
An ignition coil or module going bad causing the misfires.
A crank shaft position sensor.
A leaking fuel pressure regulator (FPR).
Bad computer (PCM).
Need to find out what cylinders are misfiring, then diagnose why. - Are those cylinders loosing spark, injector pulse ?


Ignition Turns With Key Out

2003 Pontiac Grand Prix
Engine Size : 6 cyl
Question Here: when you turn car off with key engine turns off but does not shut everything off then when you easily remove key you can still turn ignition and start and drive car.

Answer: Sounds like you have a problem with the ignition cylinder and / or the ignition switch. If the key turns all the way off but things still have electrical power, then the ignition switch is the most likely cause. If it turns with the key out, then the ignition cylinder is faulty. The ignition cylinder is what the key goes into, and sits inside the switch. the ignition switch feeds power to most of the car systems.


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  • Guest - eddie

    i have a 1998 pontiac gran prix gt 3800 v6 its stalls when i give it gas

  • Guest - Mary

    Need diagram for installing alternater replacing.