My Pontiac has some issues. The original problem was it would run fine until it got to op temp, but when you shut it off you would have to let it cool down for about an hour before it would restart. It would crank but not fire, then when it cooled it would start fine. Took it to my mechanic and he tested some things and discovered it only had 28psi out of 50psi fuel pressure. He replaced the fuel pump and it seemed to run better, but after I picked it up it did the same thing I took it in for. I did some research on my own and found out it could be the ICM. I replaced the part and the problem went away only to be replaced by a new one. Now the car misses out, stalls at idle and the tach behaves erratically, usually reading between 3k and 6k rpm and frequently bouncing the needle so hard you can hear it slap. It seems to run a little better after it heats up, but it is still sluggish and misses and the tach still bounces. It doesn't throw any codes other than egr, I checked the valve by unplugging it and the car wouldn't run at all. I checked the MAF by unplugging it and there was no change. It is a 2002 SE 3.1 with 120,000 miles. It has had extensive work done to it including intake gasket, timing cover gasket, crank sensor, fuel pump, fuel filter, water pump, thermostat, new battery plus suspension work. Any input is welcome, I'm inclined to believe it is coil packs and wires, but I want to make sure before I start throwing money at the problem.
2002 Grand Prix stalls, misses, erratic tach
- Thread starter Dobbs
- Start date
ibhuff
New member
I've come across At least 4 of these motors with similar characteristics. Misfires, stalling, idle speed jumping all over the place. but usually accompanied by a p0300 random misfire. each time it was the fuel pressure regulator leaking. The FPR is attached to The fuel rail, disconnect the vac line to it while its running and see if fuel is leaking out.
Oh and the resistance specs for the coil packs can be found easily online or even in a haynes manual.
Oh and the resistance specs for the coil packs can be found easily online or even in a haynes manual.
For what its worth I ran into a similar problem a while back.. Car came into the shop showing the exact same symptoms.. almost acted like you were quickly turning the key on and off really fast but other times it would run and idle just fine.. after quite awhile of pulling out my hair, calling it everything but a Pontiac, and hooking it to several computers with no luck I finally had a thought that bad ground could cause this.. So I changed out the ground wires both to the motor and the chasis even though they looked fine and wouldn't ya know it the problem went away.. and to my knowledge hasn't been back.. I guess my lesson was even though the ground wire looks ok after time I guess they will start to break down internally due to a small defect or nick in the insulation or who knows what.. hope this helps!!