Cleaning the throttle body gone bad

[gman]

The IAC if you did not remove it may have uncoiled itself. You may want to remove it. The IAC is held in place with just 2 torx screws and a connector. When removed you can depress the plastic based spring portion into the body with one hand and wind the spindle back into the body. It's recommended positioning is measuring from the pointed top of spindle to the base of IAC, spindle should extend a little under an inch. if you have it out normally I would clean it with some Carb Spray and then shake it drain it dry, spray a little WD 40 in it shake it out let it dry a little clean it's passage in the throttle body and reinstall it.

 

[gman]

In reference to the IAC, if you did not remove it may have uncoiled itself. You may want to remove it. The IAC is held in place with just 2 torx screws and a connector. When removed you can depress the plastic based spring portion into the body with one hand and wind the spindle back into the body. It's recommended positioning is measuring from the pointed top of spindle to the base of IAC, spindle should extend a little under an inch. if you have it out normally I would clean it with some Carb Spray and then shake it drain it dry, spray a little WD 40 in it shake it out let it dry a little clean it's passage in the throttle body and reinstall it.

 

[BIGSLVRXJ]

Looks like ya accidentally posted twice. Nah I replaced the IAC all together, even the old one was still coiled though. Thanks for the input though.

 

[pxs]

This happened to me as well. it was idling at around 1200.. I adjusted the throttle stop (or idle adjustment, as i've heard it called) and it was fine. I only adjusted it like 1/2 a turn...
It's on the back side of the throttle body and adjusts with an allen wrench.

Good luck.
-Nick

 

[BIGSLVRXJ]

It did end up being the idle stop adjustment. I wonder why it changes when you spray the throttle bodys out? Anyway, I got her idling at about 800 now so everything is good. Thanks for the help guys, couldn'ta done er without ya.

 

[HJ88]

There isn't a line from MAP sensor to TB on pre-'96 4.0's. The vacuum line from the MAP sensor goes directly to the intake manifold.

I have an 88' and the vacuum line on mine goes from the MAP sensor to the TB.

 

[HJ88]

It did end up being the idle stop adjustment. I wonder why it changes when you spray the throttle bodys out? Anyway, I got her idling at about 800 now so everything is good. Thanks for the help guys, couldn'ta done er without ya.

it may have been a bit of gunk plugging up around the butterfly and after you cleaned it it may have been letting more air by or something... i dunno just a thought.

 

[Dr. Dyno]

SPOBI alert!! Sorry Dr, my 89 has the MAP sensor vac line plugged into the throttle body. Occasionally this line wiggles loose on the TB end, which causes the Jeep to run like crap. Not really sounding like this is your problem though.

The MAP sensor vacuum line may indeed be plugged into the TB on '87-'90 Renix models but on '91-'95 HO's it goes onto the intake manifold.

 

[Jeep839]

so what type of tps do you have (maker) and where did you get it that you have a lifetime garantee?

 

[Tom R.]

so what type of tps do you have (maker) and where did you get it that you have a lifetime garantee?

Borg Warner.....I'm pretty sure you'll find it at AutoZone

 

[BIGSLVRXJ]

Borg-Warner at O Reillys. Im sure autozone would work too though. It was pricey though like 80 bucks.

 

[Jeep839]

what's this lifetime warranty all about. what will they give you a new one for???

 

[BIGSLVRXJ]

you take it back to the store, say its failing, and they give you a new one.

 

[Jeep839]

how much does it cost???

 

[BIGSLVRXJ]

Its free man, thats why its called lifetime warranty. If you're talking about the price of the original TPS its like 70 bucks I think.

 

[daddyphatsacs]

So, would a bad/ dirty IAC cause it to idle very low too? My 2001 Cherokee stalls at intersections when idiling. I'm going to try to pull off the IAC and clean it up a bit tonight. Any recommended carb cleaner? Any tricks involved?

 

[Neil]

DON'T LET THE PLUNGER FALL OUT!!! That usually ruins the IAC. Mine fell out, it took a while to get it back in right but I got it. Most people aren't as lucky. Cheap carb cleaner and an old tooth brush work great. I also used a small piece of copper wire to get in the hard to reach places. Be careful and use copper not hard wire so you don't leave any scratches. I would also check all of your vacuum lines, sometimes small almost invisible cracks develop and can cause stalling. Good luck, the IAC is usually nasty dirty. When I cleaned the passages in the TB I used my shop vac to suck all of the junk so it didn't fall down the intake.

HTH,
Neil

 

[daddyphatsacs]

Great info, thanks. How do I check for vacuum leaks? I'm pretty new with all of this. Do you think it's the IAC?

 

[5-90]

There isn't a line from MAP sensor to TB on pre-'96 4.0's. The vacuum line from the MAP sensor goes directly to the intake manifold.
jeepguy1990, I suggest that you disconnect the negative battery lead for a few minutes to reset the PCM and then see if the idle speed drops back to normal.

That depends. On RENIX, the MAP sensor line goes into the passenger side of the throttle body, in this goofy little fitting/bung that likes to drop loose (I recently had to show my wife how to fix hers, since it started doing it.)

I really need to dig up a tbody somewhere and see about putting a barbed fitting on there, so the hose doesn't drop loose...

I haven't seen the OBD-I/HO setups lately, so I don't remember how they're done - but most MAP sensors I've seen otherwise either connect to the intake or at the base of the throttle body.

5-90

 

[RichP]

Just for future reference, most of the spray type FI cleaners are NOT plastic friendly, they tend ot melt it... I spray the bore of my TB but ONLY with the engine running and I keep it away from the slots and holes and such. Once I year I pull the TB and bench clean it but all the sensors come off..I use CLP breakfree on the tough carbon deposits.