5.2 stalling

[nonnie]

My ZJ has a problem w/intermittant stalling.Mornings when cold it will idle fine.When I put it in gera to back out of my drive way.--it dies. I need to run it like a bad carburatered rig; you know gas/brake at the same time. I have used gas line anti freeze, plugs,wires,I use high test only. I've change air filter and cleaned the throttle body.It sometimes stalls when warm too at stop lights. i asked a mechanic friend and he suggested the IOC. An air controller on the back of the throttle body in the shape of a triangle? Clean it w/carb cleaner. Has anyone done this. Thanks in advance. BTW 5.2 has 192,000kms/115000miles

[Jeepinabox]

I have seen bad IAC motors and carbon clogged passages in the throttle body.
This may seem like a lot of work to do but 90% is done at the bench.

Remove the four bolts from the throttle body (13mm)
Disconnect the cable and both wire harnesses (TPS and IAC)
Remove the TPS screws (torx bit) and take note of position of sensor and spring load on sensor
Remove the IAC screws (torx bit)

Clean the hell out of the throttle and where the IAC mounts and the connecting passage.
I personally like Mopar penetrating oil, it softens the carbon so you can wipe it away and will not dissolve a plastic toothbrush like throttle body cleaner.

Carefully clean with a damp cloth the IAC cone.
Slightly pull on the IAC to see if its loose, not too much or you will break it.
It will almost fall apart if bad.

Reassemble throttle body and make sure it opens all the way, if not your TPS is installed wrong.

Then bolt it on, no new seal needed if you didn't tear it.

[nonnie]

Thanks for the reply.EGR valve was a possibility too.Or so I'm told.

[gearhead313]

The EGR will usually make it idle rough or just run rough in general. It would be a good idea to clean it with your milage, but I wouldn't count on it fixing the stalling problem.

Did you recently run the battery dead or in anyway reset the computer by loss of power? If so I've noticed mine with 150k had problems with the idle air control valve re-learning too slowly. This would cause mine to stall after coming to a stop were it wouldn't keep up with the proper idle settings.

Cleaning the IACV will help if its gum'd up at all. Try it out and see how it responds.

[nonnie]

My battery light blinked on once last week. My negative cable was loose. I cleaned the IAC on the rear of the throttle body. No stalling and my fuel milage went up from 13.7mpg to 15.2mpg.wow! The JEEP seems to shift better when cold too. I am crediting the cleaning with all this! I recommend this.

[Jeepinabox]

I have seen black carbon build up in less then 20,000 miles.
Whenever I ran my finger in a throttle body and it comes out black.
I would have the service writer sell half an hour.
The only proper way to clean a throttle body is by taking it off and removing the sensors. TPS doesen't like chemicals and you can't clean the passages with the IAC in the way.