97 Grand Am 2.4L problems

[OSUPilot4]

Hello,

I am working on my 2.4l Grand Am and I am having extreme problems with it. The problem that I am having is a strong hesitation when I try to press the gas. The car seems to hesitate when I press the gas down quickly or at any point when I am trying to go uphill. The car will hesitate and misfire so bad going uphill that I will slowly lose speed and will inevitably lose about 20mph going uphill (well depending on the grade of the hill). The engine will produce a louder noise while it is hesitating, but the rpm's will usually stay the same or slowly decrease while it is hesitating. Note: The hesitation seems to be random it will not hesitate in any specific gear or at every hill, but it will at most.

I have already replaced many different components only to find that it has not changed the problem; these include the MAP sensor, TPS sensor, plugs, wires, coils, fuel filter, engine mount (which was going bad anyways). I did run Sea Foam through the manifold and that made the hesitation less frequent and less sevear, but it did not fix the problem. I put a screwdriver up to all four of the fuel injectors and could hear them all clicking so they are in working order. The car also seems to misfire once and while at idle, and will misfire worse when it the engine is cold. The last strange thing is that the engine will hesitate when the car is in neutral / park and you press the gas down hard, but it is much less sevear then when the car is in drive.

If you could offer any advice it would be greatly appriciated. I have had many mechanic friends that are confused with what the cars symptoms as well. Thank you again.

P.S. The only trouble code the car is registering is P0300 which is random misfire. There are no other trouble codes that the computer will bring up.

[xeroinfinity]

Welcome to AF !

THe only thing in the ignitions system I see you didnt mention replacing was the ICM, which cuold cause this misfire and hesitation.

Have you checked your IAC ?
Might clean that out and see if it runs any better.

Id also test the ohms on the injectors they too can cause this.
Acrossed thier circuits, it should be be between 1.95 - 2.3 Ohms. If its not the injectors bad.

Other then that might check the compression.