XJ shit the bed.

[cityslicker]

My girlfriend got stranded on her way to work today,
The jeep just shut off,
Starts fine, then at stop light/sign, the idle drops and she sputters out.
No engine light, I am at a loss.. could a vacuum leak cause this?
I haven't gotten to check it out yet, I'm hoping maybe bad gasoline... I would think o2 sensor, but there would be a code right? CPS wouldn't start... fuel pump? that would throw codes too tho,,, wouldn't it?

Any input would be greatly appreciated. The heep usually runs like a clock,, don't steer to great but purrs

[skeebs]

I.A.C.

Cleaned it recently, or ever? My wifes XJ did the same thing.

http://www.jeepforum.com/forum/f13/h...-valve-756934/

[Super Scout]

It will still start with a CPS failure and you wont have a check engine light either. Libs Jeep did the same thing turned out to be the CPS. Changed it ran great for a month and did it again. Replaced the PCM and it has run fine ever since. Good luck It might be something simple or a giant pita.

[cityslicker]

I have cleaned the IAC b4, but that was a couple of years ago, I'll clean it again. and I replaced the CPS a couple years ago too; I'd be disappointed if it was that. But when it went bad the truck would even start..
Fuel pump makes sense to me, since "pump looses pressure during idle"
does anyone know how I check that.. I'll do a search, sorry. NM

[5 SPD XJs]

there is a fitting on the fuel rail to put a guage on. 44lb low end 54lb high end. high or low is bad. low may be the regulator or the pump

[tjblair]

I would. Start with the IAC or the TPS.

[joshs1ofakindxj]

IAC or TPS. I would think fuel delivery is the problem if it was cutting out at higher RPM, not at idle. When it dies on you, go to the fuel rail and push in the valve to see if pressurized fuel shoots out as an easy check.

[DMG]

Stop by the shop and we will check for codes

[cityslicker]

OK, there were no codes, However I got this worked out, For now. Thanks to Sleeper for the step by step.. and I'll share with you.. I got it running and pulled the IAC TPS one at a time to see the changes, this is after I pulled the throttle body and IAC out and cleaned the shit out of them, (wasn't as bad as the last time I had done this). then to my shigrin, It seems I should have disconnected the battery b4 doing all this, so as to not loose the idle setting, because Afterwards every time I'd start the heep it would be at a different idle... this is where Sleepers cockamamie scheme worked out.. I unclipped but left contacted the IAC, pulled the throttle till it sounded like a good idle, I yanked the IAC off, killed the engine and undid the positive battery terminal, then touched the positive wire to the AC compressor(to reset the CPU) then let it sit for 20.. hooked it all back up, and it sure enough idled right where I had set it, just under a grand.. then I undid the negative terminal and let it sit for 20 to erase the codes that came up from pulling the sensors off while she was running..

I'm just amazed it worked.. that's never my luck.. It should have been a missing piston head or something ridiculous to keep to par with my luck..
SO Yinz were right IAC.. thank you. Thanks for the offer DMG, and thank you SLEEPER.. that shit was off the wall but you know your shit man.

[skeebs]

Good deal, glad you got her runnin again.