i have a 92 trans am with 305 tpi auto. this car has been running great until i took a trip to guthrie a couple of days ago (2 hour trip there and back) i noticed the problem about 3/4 way back home it started idling rough (before it idled perfectly smooth) when you accelerate it gets worse and its really bad around 2000 rpm. above about 2500 it gets better but does not go away. and it does not have the same power it did before. it has fairly new spark plugs, wires, cap, and rotor, i just replace the coil today (failed resistance test) it did not help. and i am not getting any codes. i am stumped on this one. i checked the TPS, and idle air. i dont know where to go next. it is rough enough it should be getting a missfire code but its not. any help would be gratly appreciated.

the engine is bone stock all i have done is removed a/c, smog, and modified air box.

 

Have you changed your fuel filter

 

i changed it about 4 months ago it seems like more of a spark issue

 

i fixed the problem a couple of days ago it was the distributor control module it failed the resistance test, A/C crank test, and wave form test. so i replaced it and it has more power than it ever has, and idles perfectly when im sitting on still i cant tell the motor is running it is extremely smooth this little 305 has surprised me.