Have a laredo sometimes when you start it goes into high idle (3000 to 4000 rpms) and stays random lengths of time also has started randomly shutting off help please

 

clean the iac lately

 

Ummmm no what is an iac?

 

The Idle Air Control (IAC) is mounted on the back of the throttle body. The valve controls the idle speed of the engine by controlling the amount of air flowing through the air control passage. It consists of a stepper motor that moves a pintle shaped plunger in and out of the air control passage. When the valve plunger is moved in, the air control passage flows more air which raises the idle speed. When the valve plunger is moved out, the air control passage flows less air which lowers the idle speed. Over time and miles, the IAC can get carboned up which can have an adverse affect on idle quality. Cleaning the IAC may restore proper function and is an easy procedure to perform and good preventive maintenance so it is never a bad idea.

CLEANING THE JEEP 4.0 IDLE AIR CONTROL

Remove the air filter cover, associated hoses and the rubber boot that goes from the air filter cover to the throttle body. Remove the IAC with a torx driver (2 bolts; one can be kind of hard to get to)

“Gently” wiggle out the IAC from the throttle body. Gasket on the IAC can be re-used if it is not damaged

Clean the IAC with a spray can of throttle body cleaner; inexpensive and available at any place that sells auto parts. Throttle body cleaner is recommended rather than carburetor cleaner as it is less harsh, safe for throttle body coatings and is best for this task. Use cleaner, a rag and a toothbrush and or Q-Tips. Be gentle; don’t twist or pull on the pintle that protrudes from the IAC as it is fragile and you could damage it.

Thoroughly spray clean and flush where the IAC seats in the throttle body with the same spray cleaner

It is also a good idea to clean the entire throttle body itself, the butterfly valve inside of the throttle body and all associated linkage as long as you have things disassembled

Reinstall IAC and check idle quality

 

I actually replaced tht wirh a new 1

 

How did it work out for ya?

Sent from my iPhone using CherokeeFM

 

Helped some does it less but still hitting the high idle

 

haha. o2 sensors. just for the sake of saying it, has it been on a code reader?

 

renix sensor testing procedures http://www.lunghd.com/Tech_Articles/...iagnostics.htm

 

I'll have a look at tht article and see but I tried jumping out connector 6 and 7 like the haynes manual said and it flashed no codes but keep in mind the only check instructions I could find were 4 v-6 and ours is an inline. Sigh

 

I'm wondering if maybe there isn't a short in the writing harness. How likely a possibility is tht?

 

4.0 renix will not store codes hence will not give any each sensor must be checked according to the link posted above

 

1984-1986: Can pull limited codes

1987-1990: RENIX. No codes. Can only get data "real time" which requires specialized equipment

1991-1995: OBDI: Can retrieve codes using below link
http://www.go.jeep-xj.info/HowtoECUcodes.htm

1996-approx mid-1997: OBDII, but can use above technique to retrieve codes

Approx mid- 1997-2001: OBDII, can ONLY retrieve codes using a code reader or a scan tool

 

Sweet thank you i'll just have 2 check them all