Idle issues

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Aug 21, 2015 | 08:48 AM

#16

extrashaky

Banned

Joined: Feb 2014

Posts: 2,379

Likes: 18

From: Florida

Year: 2000

Model: Cherokee(XJ)

Engine: Golen 4.6L

You might also look for a vacuum leak. Mine did something similar when the stroker was first put in it. One of the vacuum fittings on the manifold was missing its little black cap. Massive vacuum leak. I found the cap under the ECM, stuck it back on, and everything was fine.

Aug 21, 2015 | 12:18 PM

#17

OGCollard

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Joined: Jul 2015

Posts: 15

Likes: 0

From: Omaha

Year: 39

Model: Cherokee

Engine: 4.0 the only one that matters

Thanks for the tips guys. I am going to test the iac and tps with multimeter tomorrow, hopefully get the battery load tested, and start looking for a vacuum leak. I did a quick scan after i got done with engine for any missing caps and did not see any but this requires a second look now.

Aug 21, 2015 | 12:21 PM

#18

OGCollard

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Newbie

Joined: Jul 2015

Posts: 15

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From: Omaha

Year: 39

Model: Cherokee

Engine: 4.0 the only one that matters

So...at the risk of sounding lazy....anyone have a link to the vaccuum line diagram for a 2000 cherokee sport 4.0?

Aug 22, 2015 | 12:03 AM

#19

cruiser54

::CF Moderator::

Joined: Aug 2011

Posts: 43,971

Likes: 1,579

From: Prescott, Az

Year: 1990

Model: Cherokee (XJ)

Engine: 4.0

Quote:

Originally Posted by EZEARL

GOOD! Now I'll know where it's at when I need it.

I got the specs for the test from an engineering site a few yrs back. Lost it in a computer crash. They never gave any brand or vehicle specifics but the ohms values given are what I got when I tested my new one and what I didn't get from my old one. I'm going to be pulling the one off the wife's Blazer soon and plan on testing it.

Keep in touch.

Aug 22, 2015 | 11:25 AM

#20

OGCollard

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Newbie

Joined: Jul 2015

Posts: 15

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From: Omaha

Year: 39

Model: Cherokee

Engine: 4.0 the only one that matters

Okay so i did a power check on iac plug, 12.12 volts. Did an ohm check and it came up a-d 50 b-c 50. Took i ac out and plugged it in, had someone turn key to on position. You can fee km it do something on the inside of the iac motor but i expected more rotation or upin and out movement from the pintle. It moves but barely. Anyone know how much that is supposed to move?

Aug 27, 2015 | 07:45 AM

#21

OGCollard

Thread Starter

Newbie

Joined: Jul 2015

Posts: 15

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From: Omaha

Year: 39

Model: Cherokee

Engine: 4.0 the only one that matters

Well put a new iac in. The idling stepped up to 700 where it should be. Still dies though. Although it has not left the driveway yet. I know cherokee computers are slow learners so i wonder if it just needs some miles put under it to map the new iac. The only sensor i would have left to replace would be the TPS which is only a year old. Oh, and i have not replaced the O2 sensors

Aug 27, 2015 | 08:11 AM

#22

EZEARL

CF Veteran

Joined: Aug 2009

Posts: 5,676

Likes: 301

From: WV

Year: '96

Model: Cherokee

" i expected more rotation or upin and out movement from the pintle. It moves but barely. Anyone know how much that is supposed to move?"
It moves in small increments.

Idle sounds right. You can try driving it a bit and see. If that doesn't do it try polishing the probe (or do this before driving if you want) on your CTS(coolant temp sensor)which I believe is on the t-stat housing. It to effects the fuel/air mixture. Of course your o2 sensors should be replaced if you don't know how many miles are on them. I've read anywhere from 80k to 120k is about the life for them.

Cruiser54,
I haven't forgotten the Blazer IAC test. It's on its way from Rock Auto. Ran into a problem with two of the o2 sensors.