Jeep won’t idle

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Feb 28, 2018 | 11:30 PM

99xj kfoster

Thread Starter

Newbie

Joined: Feb 2018

Posts: 5

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Model: Cherokee(SJ)

Jeep won’t idle

I have a 99xj and I can only get my Jeep to start and stay running by holding the gas. I have replaced the iac, map sensor still can’t get it to idle right . Motor is fresh rebuild with 10,000 on it. Has a full tune up even replaced oil pan and oil pump any help on what to look for would be great thanks

Mar 1, 2018 | 09:51 AM

michaelo

Junior Member

Joined: Jun 2015

Posts: 34

Likes: 1

From: South Germany

Model: Cherokee

Engine: 4.0

Did you change the TPS?

http://www.rockauto.com/de/catalog/j...sor+(tps),5136

Mar 4, 2018 | 12:39 AM

99xj kfoster

Thread Starter

Newbie

Joined: Feb 2018

Posts: 5

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Model: Cherokee(SJ)

Ya I have also replaced the tps sensor. I went out today and it started but had really low idel. I noteces it had a small air leak out of the back pvc elbow near the fire wall would that cause it do idel low or keep throwing the p0505 code

Mar 4, 2018 | 05:59 AM

tjwalker

CF Veteran

Joined: Nov 2010

Posts: 5,840

Likes: 117

From: In the middle of Minnesota!

Year: 1999

Model: Cherokee

Engine: 4.0

Follow the code.

If you still have a P0505, there is still an issue with the idle air control "circuit". I know you replaced the actual idle air control unit, but the entire circuit consists not only of the IAC itself, but the connector and wiring for that sensor.

Get some contact cleaner and thoroughly spray the connector for the IAC. Perform a very close inspection of the connector for the IAC and also the wiring leading to it.

Also be sure that your battery is up to snuff. A marginal battery can result in stalling at idle. And yes, you can have a battery that is strong enough to start the engine but marginal enough to give the engine management system fits.

Mar 4, 2018 | 03:16 PM

99xj kfoster

Thread Starter

Newbie

Joined: Feb 2018

Posts: 5

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Model: Cherokee(SJ)

Ya also replaced the tps and cleaned everything really well

Mar 4, 2018 | 03:22 PM

00t444e

CF Veteran

Joined: Nov 2015

Posts: 3,636

Likes: 469

From: Southern OH

Year: 1997

Model: Cherokee(XJ)

Engine: 4.0

How is the battery? I had the same issue with mine and the battery was still testing good but it the voltage was too low on startup and it wouldn't idle. I replaced the battery and it fixed it, my friends jeep had the same problem and was fixed with a new battery.