I just did the jeep throttle body mod but it keeps idleling at 4000rpm, I plugged the IM and used the jeep iac tip. I tryed the tip every length possible. ONE MAJOR THING Is their is a slight gap between the butterly valve when its fully closed. Please help

If you are ABSOLUTELY positive that the IAC tip is out and the hole in the IM is plugged and leak free, then it would be that gap doing it.

There should be a very minor gap no? Unless that throttle body has some sort of idle bypass. Did you put a new gasket on in the process?

No, there shouldn't be a gap at ALL. That's what the IAC is for.

ok guys i tryed everything but still idle staid at 4000rpm i went out and bought a new tb and bored it with the butterfly on. Then removed it to better even it out but in the end i still got a ring of light but honestly is soo thin that i cant believe it would make a diff. so i get everything set and istall the new tb and first it idled at 2000rpm ajusted alittle more and got it to 1300rpm but when i hit the gas it goes out of whack and back too 2000rpm........give me some tips?

i just did the 4.0L throttle body on mine and i got lucky with my iac but was a retarded and messed with it again but make sure that the butterfly valves numbers is towards u not the intake manifold one side has numbers and one doesnt.but get some carb clean or intake spray and double check for vaccuum leaks cause my iac housing was leaking. let me know wat u find ill help as i go with tuning my throttle body.

For the hanging idle check the tension of the spring. And what I mean is that the throttle plate has some force holding it closed.

Also, make sure that the spring is not binding against itself.

Originally posted by teklein
For the hanging idle check the tension of the spring. And what I mean is that the throttle plate has some force holding it closed. Also, make sure that the spring is not binding against itself.

hmmm...well i did cut 2 lines off the spring but when it was out i checked it and it closed fine and didnt jam up or anything. I also used the eclipse spring insted of the jeep one would that make a diff?

I had idle and coasting issues with my MP 60mm TB that I was able to get rid of by doing two things: 1. Set the throttle spring to the tighter setting. 2. Remove and thoroughly clean out the IAC with R/C electric motor cleaner.

Since hten the car idles spot on at 750 RPMS and never hangs during coasting in neutral.

Worth a shot..

ok well i got good news car idle at 1000 which it did b4 the only problem is when i step on the gas.....then idle will stay at 2000 but when i turn the the spring thing wit my hand itll return back to 1000rpm.. So i know for a fact its a spring isue i will try to cut off more coils form the eclipse spring but if not i will try to use the jeep spring. Thanks for all the help guys