high idle after warm up

Post your Jeep related Tech here.

Moderators: Toyman1994, TallGuy, Tice, Ashman

high idle after warm up

Unread postby azbwhunter » Sun Aug 16, 2009 6:23 pm

My 90 Cherrokee 4.0 L idles normal but after a few mins. it idles very high. I have checked for vacumm leaks and all connecttions but i am at a loss.. Any suggestions ?? :mad2: Thank you
User avatar
azbwhunter
Training Wheels
 
Posts: 19
Joined: Sat Aug 15, 2009 6:58 pm

Unread postby scrambler 82 » Sun Aug 16, 2009 7:25 pm

Does it give any codes?

Maybe IAC valve?


?
D60 rear, 60 front 3 linked, spools, 5.38's and 39.5 IROK's, auto and a little 6 banger!
User avatar
scrambler 82
Top Dawg
Top Dawg
 
Posts: 1818
Joined: Thu Jan 19, 2006 7:29 pm
Location: Kearny,Az

Unread postby azbwhunter » Sun Aug 16, 2009 7:44 pm

Havnt hecked codes yet thats my next step thank you
User avatar
azbwhunter
Training Wheels
 
Posts: 19
Joined: Sat Aug 15, 2009 6:58 pm

Unread postby scrambler 82 » Sun Aug 16, 2009 7:46 pm

Also, you have a pm.
D60 rear, 60 front 3 linked, spools, 5.38's and 39.5 IROK's, auto and a little 6 banger!
User avatar
scrambler 82
Top Dawg
Top Dawg
 
Posts: 1818
Joined: Thu Jan 19, 2006 7:29 pm
Location: Kearny,Az

Unread postby Ashman » Sun Aug 16, 2009 9:08 pm

There is the Throttle position sensor (TPS) and Idle control actuator(ICA) Clean those and it may fix your problem.

I had this Cherokee tech put in the pirate jeep bible.

Super bad ass dave... wrote:http://www.pirate4x4.com/forum/showpost.php?p=8608164&postcount=7

TPS (Throttle Position Sensor)
special order from checker about $55, can cause hesitation and stalling when retuning to idle, also see EGR
First clean all connector connections and sensor using Carburetor cleaner and electrical contact cleaners.
TO TEST:Use a multi meter to test the three wires. Orientation of the three wires may differ, but one is a ground one, is 5V source,
and one is .75V signal. Do all tests with the engine off and the key in the on position.
First find the ground, put meter on ohms setting, and put one terminal on the clean ground terminal,
the other terminal probe the TPS signal wire. I use T-Taps to tap into the wires so not to hurt the connector. My ground wire showed 15 ohms,
Not great but not TOO bad, Some guys jump this wire to a better ground. Now put your Volt meter on volts setting and
probe your ground on the connector, and look for the 5V source, 4.5V is acceptable. Try with respect to your battery ground also.
Next test your signal for about .75 volts at idle. If it has no voltage at idle its BAD, but if it has the .75 volts, you then need
to slowly move the throttle from idle to open, looking at the voltage to make sure it slowly rises with the
throttle movement upward. If the voltage hops and is not a nice even rise, replace the sensor.

ICA (Ignition Control Actuator) special order from checker, when faulty causes a high idle at like 2000RPMS at start up and will slowly level out.
First clean the throttle body(TB) and ICA sensor with carb cleaner, located next to the TPS on the TB,
Also clean all the connectors.

EGR (Exhause Gas Return) Is a vacuum controlled valve that allows exhaust to circulate back to the intake,
When the diaphragm is ripped or gunked up it may cause stalling at idle. Clean with carb cleaner, $80 ish dealer replacement.
User avatar
Ashman
Site Admin
Site Admin
 
Posts: 5449
Joined: Wed Nov 27, 2002 11:14 am
Location: Vail, Arizona

Unread postby azbwhunter » Mon Aug 17, 2009 1:55 pm

Thanks guys i appretiate it changed EGR last year will check the other and clean Thanks again :thumb:
User avatar
azbwhunter
Training Wheels
 
Posts: 19
Joined: Sat Aug 15, 2009 6:58 pm


Return to Jeep Tech

Who is online

Users browsing this forum: No registered users and 1 guest

cron