rough iding

[edwadway]

Hello I’m from the South , I have an 1992 GMT400 / C1500 4.3 Liter V6
Automatic, I am having rough idle, I have changed 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.

[richard wysong]

Sounds like it may be a vacuum leak, throttle body base and insulator are common leaks, Hows the ignition system?