I have a 1987 Bronco 2, 4wd, AT, 2.9L engine.The truck has a rough Idle. I ran a diag for the codes and got 33 and 34. I replaced the ERG valve, cleared the codes, but they returned. I replaced that ERG with another one, again cleared the codes, but they re-appeared. I checked for vacuum leaks but could not find any. I am out of ideas. Any help is appreciated.

 

when i first got my '86 it had a rough idle. i replaced the Idle Air Control valve and the Throttle Position Sensor and the idle now sits at 900rpm and doesn't move.

 

Are they difficult or expensive to do?

 

they both are on the left side of the intake as you are standing at the front (you can't miss them). they are held on with 2 screws each with 2 wires running out of them. unscrew them then unplug them, plug the new one in and screw it back on and thats it. (couldn't be easier). the idle air control is about $80.00 and the throttle position sensor is about $45.00 from Ford.