studder

Ok, when I'm driving and go up a hill or have to give it light pedal it studders, almost like a cyl drop. I'm pretty sure its not a cylinder drop. It will continue to do it until I release throttle and mash it down again.

Also, when i turn the key at start up, I get nothing. I have to put it in N then it starts right up. Neutral saftey switch? And would that be related to the above issue? Guy at a shop said he thinks its IAC and said its connected to N switch?

3.3L grand am BTW

Probably a double issue...
IAC stand for Idle Air Control, notice the "idle" part
the neutral switch is located on the transmission. It connect between the ignition switch "start" position and the starter solenoid. There is no other connection but the starter.

Maybe the guy wanted to say MAF sensor (mass airflow sensor)

I'm assuming the IAC is bad, once it gets to operating temp the idle gets all funky. Is the n safety switch hard to do? And where is the IAC?

One problem sounds like secondary ignition(plugs, wires, coils)....

Second one is the P/N switch.....may be out of adjustment.....check if the rear backup lights are on in reverse...

One problem sounds like secondary ignition(plugs, wires, coils)....

Second one is the P/N switch.....may be out of adjustment.....check if the rear backup lights are on in reverse...

Park/neutral switch same as neutral safety switch?

One problem sounds like secondary ignition(plugs, wires, coils)....

Second one is the P/N switch.....may be out of adjustment.....check if the rear backup lights are on in reverse...

Yes the lights are on while in reverse

the IAC is used for idle only. If you touch the gas pedal, then the IAC is not in use anymore. The butterfly basically cut the air to the engine, the IAC is a bypass valve, allowing more air to get in, which is required while heating up AT IDLE, as it need a bit more air. Once you touch the gas pedal, it open up the butterfly, letting plently of air in.

Your first step would be to check for codes, and pending one...

As for the switch, I never toyed around that one, so I can'T say. I know where it is, but I never actually checked how to change it...

Yes, the park/neutral switch on the tranny is the same as the neutral safety switch....if it starts in neutral, and is adjusted right, then it's the switch......