jeeps4life

I have a 1990 jeep cherokee pioneer 4.0, it runs for about a minute then starts to idle roughly and the eventually dies. If I hit the gas when it idles rough then it bogs,spits and sputers but it will raise the rpms after that to a normal idle but about a minute or less its back to running rough and stalling. If I let it die and start it back up then it seems to run fine untill the next time
I stop and try to start her back up. Then the same running rough and stalling I have replaced the fuel pump and sock, fuel filter, spark plug wires, distributer cap and button. I have read that the O2 sensors can maybe do this but Im not sure. Any suggestions?

BuckB91XJ

Sounds like your throttle body and IAC needs a good cleaning to start with. The same cruddy gas we have to use that fogs over your O2 sensor will gum up your IAC. Your IAC is what controls your jeeps ability to idle or not idle without throttle input. If you have never done it or not done it lately, remove you IAC valve from the bore in your throttle body and give it and it's bore a good scrub with a toothbrush and carb. cleaner.

jd4x426

X2^

jeeps4life

I cleaned the IAC and it does not stall anymore. It still runs a little rough but its a lot better. Thank you for your help Buck and jd

Downfallofusall

Hey there ...

No idea how to do this forum thing here .... But I am having the same issue with my 1985 Cherokee V6 2.8L ... It starts up but I have to push the gas and rev up the engine or it cuts out ... Then driving normally it sometimes bogs right down and almost stalls ... I catch it most the time but sometimes it stalls out ... Thing is it seems to flood cause I can't start it up for like 15-20 mins....

I have been reading forums and can't realy seem to figure it out no matter wha. I try ... Any ideas???? Cause I don't get it ...

We have replaced spark plugs and wires, air filter and adjusted the idel speed (seems to prevent the stalling while stopped .... Sometimes)

Thanks

Scott

jeeps4life

What I did was clean the IAC (idle air control i believe) It is only two screws and is on the throttle body. Real easy just spray some carb cleaner on it and in the hole it goes in. Mine was BLACK and when i got done cleaning, it was silver. Good luck, if u have any questions then just ask.

Downfallofusall

you got any pics of where the IAC is on the carb cause i cant find the dang thing

huntingman2706217

u will have a different motor then he does so your is going to be in alittle different spot... itll be on the throttle body though... only like 2 sensors on it i think... the tps and the iat... wouldnt hurt to clean them all...

lillybug.angel

where is the throttle body / IAC in the engine? I'm having the same problem w/ my 1992 jeep cherokee. I've tried the sparkplugs, distrube caps, & wires. I would apperate your help.

NewJerseyXJ609

your throttle body is right where your intake tube comes into.. you will see a couple sensors around it.. IAC TPS and MAP

lillybug.angel

I only know very little about jeeps/ cars. Do you know where I can find a pix of it. I found this but no pixs.
The Idle Air Control (IAC) valve controls the engine idle speed and dashpot functions. The valve is located on the side of the throttle body. This valve allows the necessary amount of air, as determined by the Powertrain Control Module (PCM) and controlled by a duty cycle signal, to bypass the throttle plate in order to maintain the proper idle speed.
TESTING
Turn the ignition switch to the OFF position. Disengage the wiring harness connector from the IAC valve . Using an ohmmeter, measure the resistance between the terminals of the valve. NOTE: Due to the diode in the solenoid, place the ohmmeter positive lead on the VPWR terminal and the negative lead on the ISC terminal. If the resistance is not 7–13 ohms, replace the IAC valve.