Hello I’m from the South , I have an 1992 GMT400 / C1500 4.3 Liter V6
Automatic, I am having rough idle, I have replaced spark plugs and wires, ignition coil, rotor, distributor cap, the MAP , Throttle Position Sensor, EGR valve, EGR Solenoid, ETC Coolant Temperature sensor on intake manifold, IAC on Throttle body, still having mirrors shake at stop sign, run smooth when accelerating, but sitting at a light idling, runs bad, please help? Also changed the O2 Sensor, also replace Fuel pressure regulator, bought 2 Fuel injectors, but had one installed backwards, and need to correct it, not sure what else to do. Bought a Vapor vent valve, but don’t know where it goes.

 

Check for vacuum leaksspray carb cleaner around hoses and intake while running, listen for RPM changes. Fix that backwards injector ASAP. Also, clean the throttle body and test fuel pressure. If still rough, suspect a weak fuel pump or clogged cat. Vapor vent valve goes near the fuel tank follow the charcoal canister lines.

 

Ok I will do that today, thanks

 

With having replaced all of those parts, Im guessing that you disconnected your battery at some point. In which case, I suggest you do an idle relearn. You'd be surprised at the difference it can make sometimes. Especially on older cars such as the one in question.

 

Yes I did thanks so much