blazer 2008

MY jeep stalls sometimes and most people here says to change the IAC but I have to wait 4-5 days,noone has one in town.Is there a way to test it while I,m waiting ,is a 120.00 item.Can I unplug it to see if it runs the same ?

blazer 2008

Me again,I thought I would try rock auto and is only 50.00 shipped to me in Can.is the cheap IAC,any thoughts on rock auto?

DFlintstone

Random dieing could be the CPS. Easy enough to check;

AC voltage CPS test; Small clips on the meter leads really helps.
Unplug the connector at the back of the manifold with wires going down to the bell-housing/cps.
Probe the two wires to the cps with the meter set on AC volts. (a 200 scale on mine).
Crank the engine and note the voltage. (jump it if your battery is low)
Mine somehow works with only .3 my wiring/grounds must be pretty spiffy. .5 seems to be a good mark. One article talked of .5 to .8. **Update, it soon failed. I installed Napa #css980 in my 90.**
I forget who wrote this, be careful with the O ring if you go (here V) :
CLEANING THE JEEP 4.0 IDLE AIR CONTROL

EDIT; Upon further review, on our 87 to 90, you don't need to remove much to get to the IAC on the front of the TB. (It's the deal closer to the fuel rail) The other is the TPS.

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.

DFlintstone

I guess it has a pintle that moves in or out to control the air flow. (like an idle speed screw on older carb's)

If you unplug it, it just stops where it is.

Roler

[QUOTE=blazer 2008;2682095]MY jeep stalls sometimes...[QUOTE]

Agree with DF.

Random stalling isn't typical for a faulty IAC (but keep in mind, everything is possible in a Jeep). Does is stall when driving? Stall when idling?
The IAC is involved when idling or when taking your foot of the gas.
When the IAC ' sticks' in closed or open position, you will experience stalling idle or possible high idle.
Follow the instructions to clean it out, its good maintenance anyway.
Your CPS will be high on the list when random stalling/sputtering/stalling/backfiring takes place. If the tests show it bad, get a good quality replacement.

There are other causes as well, but go with this first and let us know how you go.

Xj88

Have you tried cleaning yours?

blazer 2008

I,ve cleaned the iac ,helped alittle a first but not lately,I have a new cps last yr.I have to feather the gas when coming to a stop or parking or it will stall but fires up right away.New battery and spark plugs.I think I will try a rockauto iac as it is only 50.00 shipped here in Can. compared to 115.00 - 175.00 at napa and they don,t have any anyways,5 days he said

salad

lol NAPA only cares about commercial accounts up here. They are the most expensive shop around marking up parts sometimes 200-300% of US retail. Even PartSource is cheaper!

It does indeed as though the IAC may be shot, but it only reacts to a signal from the TPS. If the computer thinks you still have your foot on the gas it won't open the IAC. Have you tested and adjusted the TPS?

https://www.cherokeeforum.com/f51/cr...7/#post2114717

Roler

What brand? If not a quality part, it still is on the list..

cruiser54

I wouldn't replace an IAC yet.

Click on the link in my signature and do posts 1, 2, and 3 first.

blazer 2008

OK I,ll try them this week