Ok my jeep is idleing a little low and dies when stopping. its a 88 4 liter. it has 179000 miles on. tuned up a couple months ago and just put new orings on the fuel injectors. just started doin this yesterday. any help would be great. searched on here and saw alot about cps sensor but wanted more input.

thanks

 

Have you searched for vacuum leaks?

 

Disconnect IAC & check base idle. It should idle on it's own with IAC disconnected. If not adj., 2 spec, aprox. 650 rpm & yes ck. first 4 vac. leaks. Check & clean throttle body & if problem still persists replace IAC.

 

checked for vac leaks but will cheak again. also will check iac valve

 

If you had no problems before changing your injector "O" rings I would look there first. If any are leaking fuel, they are certainly also sucking air. If you had this problem before the "O" ring change then I'd go with the troubleshooting offered by the guys before me. About 90% of idle issues I've seen with a Jeep 4.0 are caused by an IAC problem or a vacuum leak.

 

checked vac lines again and cant find a vac leak. also injectors are not leaking. its idleing about 600rpms and sounds a little rough. biggest concern is dieing when coming to a stop. i can hear fuel sloshing around and i can hear my duel pump except when the fuel sloshes. its noisy all the time but when i come to a stop and the fuel sloshes i cant hear my pump anymore then come back on. idk

 

Hmmm. How long have you had it? I wonder if it's possible your fuel pickup is effed up?
I have not been in a Cherokee fuel tank yet but I do know that some other cars have problems when you don't put the pickup in there straight up and down, or the sock filter becomes clogges or folded etc.

Some things to try;
Does the fuel level make a difference?

Can you park on a decline and see if it cuts off?

 

have had it about 6 months. i will try the incline thing tomorrow. It was running fine till yesterday i was gonna swap injectors for ford injectors but the plug didnt match. didnt remove any injectors just a plug and today changed all orings and cleaned injectors and its still doin it. dont have the money to pay a shop to fix it. checked all electrical connections to and there good. idk its very frustrating

 

Just a thought. What's the oil pressure doing when you stop?

 

i dont know i have dummy lights. i have a after market tach so i know the rpms.

 

any other ideas? things to check?

 

Nah, just see what happens with the gas level and downhill angle. You don't have an oil pressure guage on the dash?

 

try taking the iac off and pushing the pintle in almost all the way. then put it back on, but don't connect it. when u start it's gonna idle really high. let it run for a minute and reconnect the harness. drive for a few minutes and see if it's mildly corrected. if it is, more than likely you need a new iac.

 

ok will try that thanks. I unplugged it yesterday and it still idled.

 

Have u checked ur fuel pressure? Should B 31psi @ idle, & 40psi with regulator disconnected. Pressure should remain constant & not leak down after shutdown. It could B a fuel pump but it's been my experience that they work or don't work. There is the possibility that fuel pump pick-up is clogging up with rust or or other debri but if U keep pressure gauge on it , it would show up. If it's idling rough check 2 make sure that EGR is not coming on @ idle either by vacuum @ valve or pintle is stuck open by carbon build up. Put a vacuum gauge on a manifold vacuum port & it should B pulling a good 20in. vac. depending on how worn ur engine is. If gauge indicates lower vac U have a leak somewhere.