Hey everyone, Ive got a 90 cherokee 4.0. It started stumbling at WOT at highway speeds, then last week started dying after giving it hardly any throttle.

Ive read up quit a bit on sensors, and narrowed it down to being the map sensor and the TPS. Which those were also the codes I had pulled, 24, 14, and 13.

I replaced the map sensor and TPS yesterday and cleaned my throttle body.
Started it up and let it run for a few minutes and it died. And the same codes are being thrown.

Any ideas?

Thanks for any help.

 

Is the IAC and EGR functioning?

 

Have you checked to make sure the vacuum line going from the map sensor to the throttle body is attached and not collasped? Did you adjust the TPS? Sure you did just checking

 

I will pull the IAC and clean it, and I read that they stopped the EGR at 1990?

 

Alright and also as jeepneasy suggested, check the vacuum lines.

 

Ok I will do some more checking tomorrow, and go from there.
Thanks for help guys.

 

I recently had a problem with mine, over time the wear and tear of DD ing stretched and broke a wire going from the TPS to the ECU and it would lose voltage and the jeep would essentially go crazy or stall out. So Trace the wires going to and from the TPS cause i got code 24 as well. To fix, patch a wire from the TPS to ECU by opening up the ECU and splicing a wire in where the wire from the TPS comes into the box (Mines Purple w/ white Strip). My new wire comes right out of the TPS and avoids the wiring harness where the old wire broke and meets the ECU again in the box. The code means somewhere in the circuit there is a variation in voltage because its "Too high or low" I cleaned everything out with TB cleaner and everything works like a well oil 4.0 HO should lol

 

Alright.. I took the TB off again last night and pulled the IAC.
It was pretty filthy so I cleaned it up, including its port on the TB..

So today I went to fire it up, it runs for two seconds and dies..
Over and over again.. lol

I checked the wiring going to the sensors and at the computer, and all check out good.

So I pulled a spark plug and it was completely black, and there was a smell of gas.

I had just replaced the plugs, cap, and rotor a few weeks ago.

Hmmmm..

 

If they're black and reek of gas then its running rich. Meaning its not getting enough air and too much fuel. Also any vacuum leaks or broken vacuum lines?

 

I just replaced the MAP sensor, and its vacuum line looks good.

But, because it visibly looks good doesnt mean there isnt a leak right?

How do I check for vacuum leaks? I gotta get this thing goin before Saturday.. Opening day for deer. lol

 

If ya can keep it running by having someone give it a little gas, get a can of throttle body cleaner and spray along the lines and intake gasket if there's a leak the RPMs will increase a little more.

 

Ok, the only way I could keep it somewhat running was by revving it around 5-6 grand or else it would die.

I will have a buddy come over tomorrow and help me look for leaks.

Thanks again.

 

Well, finally got her running. (running great in fact!)

Turned out to be the ballast resistor.

Thanks for the help anyways guys!

 

The fuel pump ballast resistor! Crap, forgot about that! LOL I thought later models didn't have them?

 

i should have mention that cause i recently broke mine somehow while replacing head gasket when i started it up to check for leaks its idle was like a nitro funny car and stumbled very bad. awesome that you found it!! BTW..like the orange on your xj, my gf is on me now to paint mine orange which happens to be her favorite color.