vk1

My 98 grand cherokee keeps stalling on me when it gets to normal operating temperature, i replaced the fuel pump, spark plugs, distributor cap and rotor button, Ignition coil, pick up coil, and crankshaft position sensor, none of this has fixed the stalling problem and I'm running out of solutions, i can't be the only person on this planet that has or had this problem, any suggestions other than cutting my losses and selling this jeep?

JPXJMOAB

5.2L or 4.0? And stop throwing parts at it.. Diagnose.. Have you checked fuel pressure at the rail? You may have a heat soak issue.

9krpmrx8

^ This. Do you have access to a quality OBDII reader? You need to look at your fuel trims. If not, then at least manually check fuel pressure and vacuum at idle when hot.

vk1

It's the 4.0, i suspect the fuel pressure is fine, when i hit the Schrader valve on the fuel rail i get a nice jet of fuel.

EZEARL

Ever cleaned the throttle body and IAC?

vk1

I have an obd 2 code reader that plugs into the computer under the dashboard, the problem is that it's not throwing any codes at all, that's why I've been throwing parts at it that i think would fix it.

9krpmrx8

But can your scanner see data? You can have plenty of problems without a CEL. You need to look at the fuel trims and such. Checking vacuum (at idle when warmed up) is also a good idea, if vacuum is down then you could have a vacuum leak somewhere. Fuel trim data can also point you in the right direction.

vk1

I've cleaned both, the throttle body and idle air control, still didn't fix it. This problem doesn't make any sense to me.

JPXJMOAB

Check fuel pressure at the rail before you touch anything else.

vk1

My scanner doesn't show data, it's just the basic of the basic, I'll ask around, I'm sure someone i know has a good one, i really do appreciate this because I'm running out of options and money at this point.

EZEARL

Try testing your IAC.


contact order in IAC - A B C D
(A to D and B to C should test 40 to 80 ohms)
(B to A and C to D should read open)

vk1

I'll definitely test the IAC, if i can get this problem fixed that would amazing.

9krpmrx8

Just remember: Air, fuel, fire. It is not that simple anymore but still a good principal to go by. However, Stalling is generally fuel related or vacuum related. I bought a party fog machine and converted it to boost/vacuum leaks tester.