89 cherokee high idle
So I have a 89 cherokee, almosy every time I start it, it instantly hits a high idle and continues to slowly climbs. I turn it off and try 3/4 more times tell she runs normally. No one I have asked has any ideas. Can someone help
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Joined: Aug 2011
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,579
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
And here's why you do 1,3,4, and 5 first:
Many of these tips were provided to me by JeepTech when I was Service Manager/Shop Foreman at a Jeep dealer from 1980 through 1992. That’s what The Book is all about. My notes from back in the day. Right from the Field Service engineers. Most were never published, until now.
Tips 1 through 5 are a great place to begin before chasing your tail with parts replacements on your 87 and 88 Jeeps. These are pretty much “haftas” in Renix Jeep ownership. You can skip Tip 2 if you have an 89 or 90. But, do them first……….
A simple multimeter is handy along with a few other basic tools……dive in and get to know your Renix Jeep.
The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, failed emission tests, and wasted money replacing components unnecessarily.
All the components listed below ground at the dipstick tube stud:
Distributor Sync Sensor, TCU main ground, TCU “Shift Point Logic”, Ignition Control Module, Fuel Injectors, ECU main ground (which other engine sensors ground through, including the Oxygen sensor, Knock Sensor, Cruise Control and Transmission Sync signal. All extremely important stuff.
The factory was aware of the issues with this ground point and addressed it by suggesting the following:
Many of these tips were provided to me by JeepTech when I was Service Manager/Shop Foreman at a Jeep dealer from 1980 through 1992. That’s what The Book is all about. My notes from back in the day. Right from the Field Service engineers. Most were never published, until now.
Tips 1 through 5 are a great place to begin before chasing your tail with parts replacements on your 87 and 88 Jeeps. These are pretty much “haftas” in Renix Jeep ownership. You can skip Tip 2 if you have an 89 or 90. But, do them first……….
A simple multimeter is handy along with a few other basic tools……dive in and get to know your Renix Jeep.
The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, failed emission tests, and wasted money replacing components unnecessarily.
All the components listed below ground at the dipstick tube stud:
Distributor Sync Sensor, TCU main ground, TCU “Shift Point Logic”, Ignition Control Module, Fuel Injectors, ECU main ground (which other engine sensors ground through, including the Oxygen sensor, Knock Sensor, Cruise Control and Transmission Sync signal. All extremely important stuff.
The factory was aware of the issues with this ground point and addressed it by suggesting the following:
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