Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here! ZJ (93-98), WJ (99-04), WK (05+)
All ZJ/WJ/WK specific tech questions asked here!

02 wj iac valve problem

Old 10-29-2016, 11:38 PM
  #1  
Newbie
Thread Starter
 
Join Date: Oct 2016
Posts: 14
Model: Cherokee
Default 02 wj iac valve problem

Hey, I'm new here I have an 2002 jeep grand cherokee Laredo 4.0l with a few bolt ons I have a new 62mm throttle body, 4 hole fuel injectors, and
k&n cold air intake. Recently after the jeep warms up.and the idle air control valve closes and the jeep idles down I can give it gas and the iac opens back up and the jeep revs up with very little gas. I replaced both the iac ,throttle position sensor, and crank sensor. When I reset the battery the jeep runs fine for a week or less and than acts up again. Also runs back to normal after unplugging the iac and plugging it back in.. I'm stumped any help would be awesome. Thank you
Trevorparkz is offline  
Old 10-30-2016, 07:33 AM
  #2  
CF Veteran
 
peep's Avatar
 
Join Date: Oct 2010
Location: Ontario, Canada
Posts: 2,137
Year: 1989 Laredo
Model: Cherokee
Engine: 4.0 L 6 Renix
Default

I have had bad IAC right out of the box twice, Belden brand both, I was suprised, and one faulty TPS, my local Napa did honour the exchange. I've had the intermittent idle problem also over a few days. On the XJ it took 3rd IAC and second TPS over three month period to correct fully, good for couple years now.
Doorman and Standard brands components have worked for me without problems and they are considered pretty basic aftermarket brands.
My local Chrysler dealer often will sell a Doorman component, not a Chrysler branded component, so OEM parts are not always available.
Check Cruisers tips, many apply equally to my XJ, ZJ, and WJ all with 4.0L.
Confirm your grounds are good, it's not just an XJ problem, all vehicles can benefit from confirmed grounds.
peep is offline  
Old 10-30-2016, 07:36 AM
  #3  
CF Veteran
 
peep's Avatar
 
Join Date: Oct 2010
Location: Ontario, Canada
Posts: 2,137
Year: 1989 Laredo
Model: Cherokee
Engine: 4.0 L 6 Renix
Default Inlaw's can make a contribution to Jeep well being.

PS: Since you've got it exposed, insure the throttle body is clean. A little decarb or brake clean spray and your brother in law's tooth brush will work!
Attached Thumbnails 02 wj iac valve problem-larrys-toothbrush.jpg   02 wj iac valve problem-dirty-tb.jpg   02 wj iac valve problem-clean-tb.jpg  
peep is offline  
Old 10-30-2016, 09:09 AM
  #4  
Newbie
Thread Starter
 
Join Date: Oct 2016
Posts: 14
Model: Cherokee
Default Thanks

Haha thank you for your response.I hope it's a bad iac right out of the box I was thinking a bad pcm because it will run good after I reset it than slowly act up again. I'll research how to test the iac. Thank u again for your time
Trevorparkz is offline  
Old 10-30-2016, 10:09 AM
  #5  
Newbie
Thread Starter
 
Join Date: Oct 2016
Posts: 14
Model: Cherokee
Default

How did you test your iac valve to find it was bad?
Trevorparkz is offline  
Old 10-30-2016, 06:59 PM
  #6  
CF Veteran
 
dave1123's Avatar
 
Join Date: Nov 2010
Location: Manlius, east of Syracuse, NY
Posts: 11,267
Year: 2000
Model: Grand Cherokee (WJ)
Engine: 4.0L
Default

JMHO, "Change it with Mopar, change it ONCE!"
dave1123 is online now  
Old 10-30-2016, 08:35 PM
  #7  
Newbie
Thread Starter
 
Join Date: Oct 2016
Posts: 14
Model: Cherokee
Default

I went back to autozone and exchanged it for another new one. I don't think the iac value is the problem. I ohm all three iac values and they all read 52. Here is another way to explain what's happening everytime i give it Gas the iac opens up full and let's alot of air in, causing the idle and power to increase.when I let off the Gas it stays reved up till the iac closes. When I unplug the battery to reset the computer it'll run ok for a few days. Found unplugging the iac for a short time and plugging it back in would also bring it back to normal for a bit Any help would be amazing can't really afford a shop to look at it.
Trevorparkz is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description: