Hey i have an 88 iroc with a tpi 305 and a 5 speed. things i have recently done to the car, new bosch III injectors, fuel pump, filter, maf, both maf relays, icm, and the man i got it from said he had just replaced the wires plugs cap and rotor. now let me just say i think the tach is off but when i start the car the rps go up to 2500 then it goes to 1200 and shudders around then evens out around 2000 but still shudders a little. But when you give it a little gas it goes up then when u let off it drops back down to 1200 shudders then evens at 2000 again. by the way it smells like its running a tiny bit rich. it could be the timing. any ideas would be great W0000000000t first post

 

I'm having a similar problem. All the suggestions I'm reading point to your idle air control valve. First, check the connections, then pull it out and spray carb cleaner into it. Make sure the carb cleaner is safe for electronics.

 

Check your IAC and make sure it's not dirty or gummed up. Also inspect for damage or gapped correctly

 

it means your car is gonna blow up, run outttt!