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  #1  
Old October 5th, 2009, 14:08
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sixditchoffroad sixditchoffroad is offline
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fyi...Idle Speed Stepper Motor - (aka Idle Air Controller / I.A.C.)

Ive been without my jeep for about 6 months driving a work truck because of this Idle Speed Stepper Motor - (aka Idle Air Controller / I.A.C.). I drove home from work one day the next morning the jeep wouldnt start, I checked everything well almost everthing turns out I had no spark. so, after new plugs, wires, rotor cap, and a ton of time looking and crawling on my jeep wondering why she had no spark, that turned out to be the 35 dollar answer. this might help someone else with a similar problem.
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  #2  
Old October 5th, 2009, 14:14
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Bryan C. Bryan C. is offline
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Re: fyi...Idle Speed Stepper Motor - (aka Idle Air Controller / I.A.C.)

While I appreciate your attempt at helping out the masses. The idle air control motor has nothing to do with a vehicle not having spark.

I can see the IAC causing a start and stall condition, but I seriously doubt it will cause your Jeep to not start at all.

Sounds like you got another problem.
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  #3  
Old October 5th, 2009, 14:28
joe_peters joe_peters is offline
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Re: fyi...Idle Speed Stepper Motor - (aka Idle Air Controller / I.A.C.)

Quote:
Originally Posted by Bryan C. View Post
While I appreciate your attempt at helping out the masses. The idle air control motor has nothing to do with a vehicle not having spark.

I can see the IAC causing a start and stall condition, but I seriously doubt it will cause your Jeep to not start at all.

Sounds like you got another problem.
x2, fully agree, IAC has nothing to do with spark. Proof? Now that it runs, unplug the IAC, it will still run.
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  #4  
Old October 5th, 2009, 14:50
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wolfpackjeeper wolfpackjeeper is offline
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Re: fyi...Idle Speed Stepper Motor - (aka Idle Air Controller / I.A.C.)

plus if it were the IAC all you would have needed to do would be to pull the battery cables for a few minutes.

If it were running erratically, pausing at odd idle ranges, or otherwise having problems with RMP ranges maybe, but it should still start. If this were the case an easy solution would be to run the RPM's up to about 4k and abruptly kill the ignition switch. It causes the stepper motor to "re-learn" its home position.
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  #5  
Old October 5th, 2009, 19:44
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sixditchoffroad sixditchoffroad is offline
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Re: fyi...Idle Speed Stepper Motor - (aka Idle Air Controller / I.A.C.)

Yeah, just trying to help. It worked for me tho. All i know is I had fuel, and no spark I checked everything X10 it got to the point I was breaking down the motor, from the top. a little bit in I found the iac was caked with build up I got a new one and she fired right up after 6 months of sitting. pretty awesome I think. speaks alot for the 242.
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  #6  
Old October 5th, 2009, 22:11
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gradon gradon is offline
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Re: fyi...Idle Speed Stepper Motor - (aka Idle Air Controller / I.A.C.)

I know it can run w/o it connected, but can the IAC short out the ASD relay(if the supply voltage is shorted)?
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  #7  
Old October 10th, 2009, 17:57
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sixditchoffroad sixditchoffroad is offline
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Re: fyi...Idle Speed Stepper Motor - (aka Idle Air Controller / I.A.C.)

Ok, I guess I stand corrected... My jeep is weird. I changed the IAC, she fired up fine about three or four times, and I was able to drive it a ways. I go to work the next morning shes fine, good after work too. the next day no startie. wtf. the search continues....
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Old October 10th, 2009, 21:10
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Re: fyi...Idle Speed Stepper Motor - (aka Idle Air Controller / I.A.C.)

does it crank and not fire, or does it not even crank?
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  #9  
Old October 10th, 2009, 21:13
joe_peters joe_peters is offline
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Re: fyi...Idle Speed Stepper Motor - (aka Idle Air Controller / I.A.C.)

Quote:
Originally Posted by sixditchoffroad View Post
Ok, I guess I stand corrected... My jeep is weird. I changed the IAC, she fired up fine about three or four times, and I was able to drive it a ways. I go to work the next morning shes fine, good after work too. the next day no startie. wtf. the search continues....
Let us start over.

Year, we know you have a 4.0, trans, transfer case and any mods you think might be pertinent?
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  #10  
Old October 11th, 2009, 09:21
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sixditchoffroad sixditchoffroad is offline
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Re: fyi...Idle Speed Stepper Motor - (aka Idle Air Controller / I.A.C.)

It cranks fine, its just wont start.. she's a 93, ax 15 and np231. no mods with a clear decisive relevance. just a throttle body spacer, I dont think that'd be the problem.
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  #11  
Old October 11th, 2009, 09:26
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Re: fyi...Idle Speed Stepper Motor - (aka Idle Air Controller / I.A.C.)

Have you checked the CPS?
A bad CPS will cause a no spark, and when they are on their way out, will allow you to start your vehicle at times, and then won't at other times.

Take a multimeter and ohm out the pins, then report back.
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