2002 Liberty Start-up and Stalling problem

[disorc]

Hello all this is my first post. I am fairly new to the Jeep game and purchased a 2002 Jeep Liberty Limited with about 85,000 miles on it. I now have 90,000 as of today. The problem started out a month ago where I would start the car up and it would die instantly. The car fired up just fine, then shut off. More recently, right after I stopped at a light, the car stumbled down to 400 rpms then shut off. I fired it back up and switched to N and kept my rpms above 500. I do have an engine light for the Bank 1 Catalytic but I don't know if its related. I have replaced the value cover because of an oil leak but since then just regular oil changes (2).

 

[disorc]

UPDATE- The IAC will not let the car go above 1000rpm

 

[CzarKJ]

Give your throttle body a good cleaning. Also clean the iac. Could be that simple a fix.

 

[LibertyTC]

Welcome to the forums!
What code number are you getting?
If I recently got a Jeep, I think a tune up may be a good place to start, and fixing any code issues.
Use throttle body cleaner inside throttle body.
The IAC controls idle, get it clean, and port, here is a few pics Link: http://www.jeepkj.com/forum/f196/vibrations-rough-idle-46693/
I would like to know what kind of spark plugs are in there and see how they are burning/color chart.
The correct NGK plugs are listed under hood on sticker, gap em at .040
54826[/ATTACH]"]

You must be registered for see images attach

Knowing fuel pressure at rail would be nice = 49.2 psi for a 2 connector PCM and 59.2 psi for a 4 connector PCM.
54828[/ATTACH]"]

You must be registered for see images attach

Is you engine light on or flashing?

 

[disorc]

thanks for suggestions, after doing some tests I realize the iac is completely shot. I bought a new one, put it in and start up/drive no issues idle.