4.0 Throtle Body on my 2.5

[Ragnorox]

So I got a 4.0 throtle body cleaned it up. Swapped what I think is the MAF to the new throtle body and started it up. It is now idling around 2K, what do I do to get the idle down, the butterfly is closed. Has anyone done this before?

[limegreentj]

clean all the other sensors, like the throttle position sensor, they might be sticky...gibson just bought one off me and did this to his jeep...i know its a long shot (LOL) but see what he has to say....god, i cant believe i just said that!!! haha

[tjblair]

^ hehe!

[Ragnorox]

I was reading that it takes a couple miles to adjust the computer to the proper idle, Just took it for a ride, nice throttle response and it up / down shifts better. As for cleaning, I have damn near mirror finish on the inside. I spent 3 hours polishing the inside (OCD). pulled the butterfly polished and polished it also.

[limegreentj]

^ you sould like me

did you clean the part where the throttle control goes? theres like a little dick looking plunger thing? mine sat for a while last year and it was sticking like that when i was getting it running

glad it seems to be workin for ya though!

[Ragnorox]

Yeah cleaned the plunger thingy do dad whats it whos its thingy, and the houseing. it's idling now around 18k, but thottle isn't closing all the way, going to pull it tomorrow and try to adjust the set screw down a bit. If that dosnt work might replace the AIC (Thought it was a MAF).

[ridgerunner97]

it's idling now around 18k

Holy shit Mark! You said you were doing some engine work but goddamn! LMAO :082: :overkill:

[limegreentj]

Yeah cleaned the plunger thingy do dad whats it whos its thingy, and the houseing. it's idling now around 18k, but thottle isn't closing all the way, going to pull it tomorrow and try to adjust the set screw down a bit. If that dosnt work might replace the AIC (Thought it was a MAF).



i have a throttle control sensor here. i dunno if its any good or not....come get it.

[village_idiot]

you gotta switch the IAC housing and motor. they are engine specific. you can keep your 4.0l MAF on hte 4.0L t-body. for a little added power, grab the gasket for teh 4.0l t-body and open up the intake manifold port to that size.

[Ragnorox]

I swapped out the IAC houseing and valve. Going to port out the manifold on the new motor. Still cant figure out the high idle most be the computer. I have read about others having the same problem with 94 and 95 YJ's.

[mxg342]

vacuum leak? Did it seal up ok?

[village_idiot]

I swapped out the IAC houseing and valve. Going to port out the manifold on the new motor. Still cant figure out the high idle most be the computer. I have read about others having the same problem with 94 and 95 YJ's.
im not having any high idle problems. did you clean you IAC housing and motr plunger thing out real good?

[Ragnorox]

Dosn't appear to be any vaccum leaks. The IAC assembly is clean.

[Sycotik Skier]

pop your negative battery cable off for like 30 seconds. That'll reset your computer and zero out all your sensors. Start it back up and let it run for a little and it should relearn all the sensors and sort out how to run properly.

[Ragnorox]

Cool, thanks Brent, I will give it a try in the morning.

[95TacoKid]

a buddy of mind got a bored out throttle body for his old car off ebay, he also experienced a high idle.

We took it for a fairly long ride and tried resetting the computer by disconnecting the battery for a while but it still had a high but slightly lower idle. The only thing I could see to cause this is that the butterfly wasnt a good fit to the throttle body and was letting too much air in even when fully closed, almost like having the throttle opened up just a crack.

You said you polished the throttle body but i would check the fit between the throttle body and the butterfly. Im not completely sure if this is what caused the problem on my buddys car but it made sense seeing as he bought the thing off ebay and it looked like a hack job... just a thought, I know you only polished it and didnt bore it out so i would think you would be ok with the fit.

[village_idiot]

what IAC motor and housing are you using?

[Ragnorox]

the 2.5

[village_idiot]

then it should run at stock idle, mine run high until i swapped the IAC's. did you install hte gasket inbetween hte t-body and manifold?

[Ragnorox]

Turned out to be a simple fix Butterly was upside down, who would have thunk!

[jlovbasz3]

So what are the advantages of the 4.0 t-body on the 2.5, more air, fuel,= more power? What is the size difference in the t-body's(inlet diameter)? And will this work on my 2000? And being on the subject of 2.5 tech do they have adjustable rockers?

[cityslicker]

Turned out to be a simple fix Butterly was upside down, who would have thunk!

you just wasted 5 min of my time with this thread! you owe me a nickle.