2.9 Idle Problems

[Ranger88]

1988 2.9 that I just completely rebuilt. Engine runs great with the exception of idling once it gets hot. While the motor is cold it is very smooth. Once up to temp engine continually surges while idiling and eventually quits. You can rev the engine the smallest amount and it runs smooth. I saw an early post that said an ETC sensor was causing idle problems. Is this a possiblity since it only does it after the engine has warmed up?

Please help?

 

[IMenriched]

yes... this could be the issue. It also maybe the air temp sensor, just behind the AIC on the upper intake. start with the coolant sensor that feed the engine computer, pretty sure that is the one your referring to.

also check for vacuum leaks

 

[Ranger88]

Thanks, I will give that a try. Have done everything I can to test for vacum leaks so I think I am good there. I'll try the ECT and let you know.