I have a 99 pontiac grand am se 3.4L V6. The issue is that it starts and idles fine but as soon as I go to accelerate it just shuts off. It did have overheating issues but right after I fixed those it started doing this. I replaced the cam position sensor and also the engine coolant temp sensor and it didnt help. I was thinking of replacing the ignition coil packs and housi g but not sure if that would fix it. There are no check engine lights or stored codes .

I would not suggest changing your coil packs unless the car is running rough. I would focus on the transmission control solenoid, when properly functioning it controls the engine idle to save gas as the car warms. Unfortunately it was found as a known defect when it malfunctions due to age, it stalls the car because it gives a wrong signal which lowers the engine idle below what is needed to keep the transmission clutch assembly from stalling the car. Since it is part of the transmission technically it will not light the check engine light when it begins to fail. I can not actually say this may be your problem since I am unable to review the work on your car but I can tell you that unplugging the solenoid will do no harm to your transmission since you are only disconnecting the communication between the transmission and idle controls. I would advise you to disconnect the plug from the solenoid and if the car stops stalling the solenoid needs replaced. It is to the right of the engine on the transmission facing you as soon as you pop the hood. I am confident this is most likely the culprit and it is not expensive to replace, it is not a transmission job but a solenoid so your local repair shop can do it if it is found to be bad. Unplugging it is actually the only way to test, if car still stalls then you have me stumped. Wish you well.

You need 2 new coils a new starter n also make sure you're us 89 gas cuase that's a good gas like shelby also make sure you're battery is new n gas pump is working if it is it's a electric problem these 99 2001 car have a mind of it's own cuase its running on a transaction on how you drive the car if you do this it might help plus get a new pressure regulator cuase this way engine will have a smooth run .when it idles if the car starts to vibrate you need a mount make sure you're coolant is clog free also these minor things can cuase big and tuff heart breaks please also put catylic converter cleaner at half tank of a gas and run it about 65 55 50 chase it will clean gunk out of that check 02 sensor

Dont forget a new starter it really keeps the the battery and starter to keep thing in check then if that dosent work fix those minor things you will be okay always remember when you drive that car try understand at that moment how it effect you're car that day everything in detail is important

I have the same exact car and had the same exact problem even went to the extreme of changing the motor and replaced the sensors that was on the old motor do the new motor come to find out even though you change the camshaft position sensor and the crankshaft position sensor behind the harmonic balancer there is a can’t crank shaft position sensor on the firewall side of the motor I was tormented for four months trying to figure this out and finally . This is 100%. The reason for your problem is the 100% fixed is the crankshaft position sensor on the firewall side of the motor under the alternator two wires to the ignition coil pack