Ignition Problem Stalling

Has anyone tried something as simple as cleaning the IAC valve? It's notorious for causing idle issues. Not to mention it's cheap and easy to fix.
 
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david camarra said:
Thought that was the same as the tps.
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The IAC (idle air controller) is what lets all of the engine's air in when the engine is idling. The TPS (throttle position sensor) reports the throttle's position to the computer.

TB & TPS Sensor Locations.jpg
 
david camarra said:
And could that cause my problem?
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The IAC provides the engine with a secondary source of air for those times you're not stepping on the gas pedal which opens the main valve plate to let air in through the throttle body. The IAC passes air through itself into the engine whenever the engine is idling and the valve plate is closed, it closes when you step on the gas to open the main valve plate.

When the IAC gets dirty, and it definitely does, it can hang up and cause idle issues to the point the engine could stall from a lack of air when you're not stepping down on the gas pedal. Cleaning the IAC with an aerosol can of throttle body cleaner would not be a bad idea at all.

With the engine idling, spray the cleaner into the 'idle air control passage inlet' which is identified in the above illustration. The IAC uses that as its source of air so at idle rpms, the cleaner will get drawn into the IAC via that inlet. The engine will stall from the cleaner flooding the IAC but that's ok, that just gives the cleaner more time to work on dissolving the built up crud. Just restart the engine and repeat at least several times, restarting the engine whenever it stalls. The IAC will only suck the cleaner in at idle rpms so raising the rpms to prevent the engine from stalling will be counterproductive. Once you've emptied a good portion of the can through the IAC, use the rest of the cleaner to clean the rest of the throttle body's interior. You can raise the engine RPMs at that point as you spray so the engine won't die.
 
I replace the IAC and the TPS and the problem seems to be gone. Thanks so much for all your help and keep your fingers crossed. If this does not fix it it will be for sale>>>>>>>>........
Dave
 
Glad replacing those items fixed your problem!

And I'll be sure in the future to ask someone if they'd rather spend $40-90 for a new IAC than $6 for a can of throttle body cleaner before typing out lengthy complete instructions on how to get the IAC 100% operational again by just cleaning it lol. ;)
 
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I'll tell you what, I've seen a huge amount of problems solved as of lately just by people cleaning their IAC.

This is one of those things that I think people should do even if they have no symptoms. It's good preventive maintenance.
 
Premature on the fix. The problem is back. And on the IAC i did the can of cleaner even cleaned it out of the jeep and it did not seem right to me so i replaced it.
But back to my problem. I'm starting to think it is the transmission not going into slip mode or what ever it does. Is there a sensor for that? Also after it does the bucking and staling when i go to go it is in neutral and takes a little to go back in gear.
 
Mrriverajr said:
Any luck on this I have the same issue on my 98 4.0
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Well mine was a automatic. I had the tranny rebuilt but it was taken out of the jeep and put back in buy my mechanic. Then sent out to be rebuilt. It was a total rebuild because it had failed. The mechanic did not clean out the cooling tank and all the shit that was in there went back into the tranny and clogged the pressure switch to the converter.
Once i had a tranny place clean everything out the problem went away. If yours is a auto you might try that. But have a tranny place that knows what they are doing do it. Other than that i tried everything else and nothing fixed it. I have sense sold the Jeep it had 299500 miles on it.
Let me know
Dave
 
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