IAC pintle position
Thread Starter
Junior Member
Joined: Jun 2014
Posts: 30
Likes: 0
From: Alabama
Year: 1996
Model: Cherokee
Engine: 4.0
Cylinder over pintle and spring movement.
Hey y'all. New at this still. I pulled a code that mentioned idle and IAC. Pulled IAC and cleaned it. I hope I use terminology that is right or close enough to right to describe what I'm talking about. I unscrewed pintle almost all the way off to clean it before it dawned on me that maybe it was supposed to be at a set position to work right. I googled and searched here but I can't find answer.
Also, I can't move pintle down at all. I can move spring and the cylinder thing covering spring and pintle neck. Is this ok or does entire pintle need to move down into the body?
Thanks
CF Veteran
Joined: Jan 2015
Posts: 1,381
Likes: 3
From: Southern Maryland
Year: 1991
Model: Cherokee
Engine: 1999 4.0L
The computer does not know where the pintle is located, it only knows the air-fuel ratio needs "more air" or "less air" and moves it as needed. If its not where it was, the computer may have to relearn, might be hard to start and idle like a turd, but it will eventually get to a place where the computer is able to take over.
Might want to do an ohms test while it's off.
I used this test on my '96. '91 thru '97 use the same IAC.
IAC ohms test:
Pin sequence;
A B C D
A to D/B to A = 40 to 80 ohms
B to C/C to D = open
I used this test on my '96. '91 thru '97 use the same IAC.
IAC ohms test:
Pin sequence;
A B C D
A to D/B to A = 40 to 80 ohms
B to C/C to D = open
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
I saw a warning in the FSM, basically don't power one up while it's out, could ruin it.
Ehall's post makes scene to me. Also I'll guess is simply screws ON. I've never heard of adjusting one.
Ehall's post makes scene to me. Also I'll guess is simply screws ON. I've never heard of adjusting one.
Been a while since I replaced mine but I remember the warning of not applying power as it will over extend and could ruin it. As far as adjustment goes there's maximum measurement from the base to the end. If it exceeds that measurement you press it back in before installation. I didn't have any problems but did compare the ohms readings between the old and new one just to be sure.
Thread Starter
Junior Member
Joined: Jun 2014
Posts: 30
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From: Alabama
Year: 1996
Model: Cherokee
Engine: 4.0
Pintle screwed as far down as it can. Black sleeve/cylinder thing not movable as it was in first pic. Does it need to be screwed in like this or loose like other pic when I install it, or does it matter?
Thanks guys. One thing I need to know. I can screw pintle down to where the sleeve/cylinder doesn't move at all. In previous pic I unscrewed it to the point that the sleeve/cylinder thing (black thing) can move up and down. Which was does it need to be. Screwed down tight or unscrewed where cylinder/sleeve and spring can move? I know general purpose of IAC, just not detail on how it works.
Thread Starter
Junior Member
Joined: Jun 2014
Posts: 30
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From: Alabama
Year: 1996
Model: Cherokee
Engine: 4.0
Not so yellow towel after cleaning throttle body.
Just update. Took throttle body off. Knew was dirty from glance. It was filthy once got out and got good look. New at DIY auto repair, but I have a feeling that throttle body this gunked and dirty IAC just might be my problem...lol
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CF Veteran
Joined: Jan 2015
Posts: 1,381
Likes: 3
From: Southern Maryland
Year: 1991
Model: Cherokee
Engine: 1999 4.0L
If you are doing all that... the little housing that the IAC goes into is also removable and has a thing gasket that gets brittle over time and leaks/whistles as a result. You can pop that off, clean it good, and use some black RTV as a substitute for the gasket. Let it set up for a few minutes (enough to form a light film) then reassemble.
CF Veteran
Joined: Sep 2010
Posts: 12,692
Likes: 6
From: Mercer County, NJ
Year: 2001
Model: Cherokee
Engine: 4.0L I6 HO
Good job getting her sorted out and keeping us posted. Doing a little lug work on our XJs go a long way. A positive attitude like you had, don't be afraid to ask us anything.
Thread Starter
Junior Member
Joined: Jun 2014
Posts: 30
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From: Alabama
Year: 1996
Model: Cherokee
Engine: 4.0
Once again thnx for replies. Also thnx for politeness. At another unnamed site I was sorta mocked when I asked a simple question. I said I was not only new working on Jeeps, but everything. Still felt like retard after they were done with me
. You guys are great. Now I think I have to start another thread if I can't find the coolant info I need on another thread here. Hopefully I'll be treated good again.
. You guys are great. Now I think I have to start another thread if I can't find the coolant info I need on another thread here. Hopefully I'll be treated good again.
CF Veteran
Joined: Sep 2010
Posts: 12,692
Likes: 6
From: Mercer County, NJ
Year: 2001
Model: Cherokee
Engine: 4.0L I6 HO
We are always here to help. As long as you're willing to get dirty we are welcoming. There will be times people mock around here but don't mind them. Just have some thick skin cause there's some good folks here.
Thread Starter
Junior Member
Joined: Jun 2014
Posts: 30
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From: Alabama
Year: 1996
Model: Cherokee
Engine: 4.0
Aarrrrgggghhhhh.
Hard start and high idling and stalling! Wouldn't turn over without holding peddle to floor again. No jerking and shaking this time though. Then idled high (1000-1100) and smelled rich. Hesitated when I got on gas while in park. Took it out to see if it'd even out. Idled high enough to roll a bit by itself then stalled when got on gas. Hard start again, rich smell and high idle. Got down drive (long straight drive) came back no stall. High idle and rich still. I assume it's same general problem, IAC, throttle sensor, map sensor. Weird that it ran good for day then did this. Guess I'll probably replace IAC since I got IAC/idle code before. Found IAC for $28 before I cleaned everything. Doesn't seem like bad price. Gonna start with that probably and go from there. Not sure how much other sensors cost yet. If any other thoughts before I start this just let me know.
Hard start and high idling and stalling! Wouldn't turn over without holding peddle to floor again. No jerking and shaking this time though. Then idled high (1000-1100) and smelled rich. Hesitated when I got on gas while in park. Took it out to see if it'd even out. Idled high enough to roll a bit by itself then stalled when got on gas. Hard start again, rich smell and high idle. Got down drive (long straight drive) came back no stall. High idle and rich still. I assume it's same general problem, IAC, throttle sensor, map sensor. Weird that it ran good for day then did this. Guess I'll probably replace IAC since I got IAC/idle code before. Found IAC for $28 before I cleaned everything. Doesn't seem like bad price. Gonna start with that probably and go from there. Not sure how much other sensors cost yet. If any other thoughts before I start this just let me know.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
I had this "canned". You DO know 96 had mid year changes. That's what I gather causes some 96 owners some grief. If your MAP sensor is on the TB, it's not the "tube" ( You might just have a little elbow).
There is a brittle little tube. It comes out of a rubber plug, low on the engine side of the throttle body. It runs back to the firewall, then up to your MAP sensor sort of high up there near center on the firewall. CRUCIAL!! The MAP will tell the ECU to dump fuel with less/no vacuum. Any crack or blockage in that line, and you won't be happy.
There is a brittle little tube. It comes out of a rubber plug, low on the engine side of the throttle body. It runs back to the firewall, then up to your MAP sensor sort of high up there near center on the firewall. CRUCIAL!! The MAP will tell the ECU to dump fuel with less/no vacuum. Any crack or blockage in that line, and you won't be happy.


