My 92 trans am 305tpi is idling rough and seems to be down on power in lower rpms i had a full tune up done to i had the plugs, wires, fuel filter, cap and rotor, air filter, and the timing set right and it made no difference so it stills idles rough and i dont know what to trying and tackle next to try and fix the problem anyone got suggestions on what might be the problem

 

Any trouble codes? I would check the fuel pressure to see if it’s within spec. Might want to try a thorough cleaning of the throttle body. One last idea is to check your TPS voltage to see if it’s erratic when opening and closing the throttle. A scan tool would also really help here to see what the computer is getting from the sensors.

 

Datalog can't hurt, is it throwing any codes? In addition to checking fuel pressure, you might as well ohm the injectors to verify none have failed since it's easy to do. Of course, they could ohm out ok and still be clogged but it's something to check.