Lets get my jeep on the trails and road again

Hello everyone, Im new here but have been following this forum for years, I have recently stumbled upon a serious problem that arose unexpectedly with my jeeps engine, I have done all the reading and trouble shooting I can on my own with no luck, thats why Im turning to you guys.

1989 jeep Cherokee 4.0l auto 160k

Jeep was running great as a daily driver until one day I parked it at work for 8 hours and fired it up to head home and found the idle was abnormally low and uneven, upon driving it I found even more issues, the motor would run normal until 1800rpm where it would act like it was stalling/missing hard, felt like all power was being lost. I was able to get it home by constantly keeping rpm over 3000, but even there i couldn't keep a consistent speed, it had to be under acceleration. There is some major backfiring threw the intake going on when I accelerate.

1k miles ago I replaced the following; rotor, cap, wires, plugs, 02 sensor, filter, fuel filter and oil. Has ran flawless until the day.

10k ago; Fuel injectors, Fuel pump and a few other odds and ends.

I threw together this video to show you guys whats actually going on. Its lengthy and boring but shows the issue.

http://www.youtube.com/watch?v=AJHCGzwiXEk

Thanks in advance for all and any help! Lets get this jeep on the trails and road again!

Anyone thinking a intake/exhaust leak could do this? Or sensor related?

Have you tested and adjusted sensors according to the lunghd site?

I might look at the catalytic converter. Give it a tap or two and see if it rattles, or get it up to temp at night and see if it's glowing red.

...and like bigalpha said, I'd remove and clean the IAC, don't push/pull on the pintle, just clean it and hit it with a spritz of lubricant. Also, check and adjust as necessary the TPS.

Mine ran like this at one time and it was my vac line from MAP to was cracked. I'm now pretty anal about checking vac lines everywhere, regularly.

I have not tested or adjusted any sensors, although I did change out IAC, TPS, and 02 sensors with no success. The lunghd site is where I should go? I also test the MAP sensor and it was good. I want to say its the crank position sensor CPS but I here if they are bad the car wont run at all. Im at a loss, will replace the intake and header gasket tomorrow to seal that up for sure.

Well found the fuel pump to be going out, Only 10lbs to the fuel rail..

ParadiseXJ said:

Mine ran like this at one time and it was my vac line from MAP to was cracked. I'm now pretty anal about checking vac lines everywhere, regularly.

Click to expand...

It only takes one time, doesn't it?