I have a 97 grand prix it run great.....when its cold but as soon as it warms up it takes a while it will start to miss here and there then a few minutes of that and you press the gas down it will spit and sputter and the tach will jump to 0 then to 3 grand. when I got it we put a new pcm in it, new fuel pump,new fuel pump relay and a new iac. I just put a mass air flow senser on it because it through a code on it. now it doesn't through any codes. I was hoping for a miss fire code are something but nothing a have a scanner it seems to be showing fine. I'm leaning toward the crankshaft senser any other input would be nice. I know the the Ignition Control Module could be a possibility any thoughts
