When the Jeep is cold, it will idle rough for bout 30 secs. Once I take off, somewhere within the first 30-45 secs it will kinda stumble, make a pop noise, and then go like it should.

Within the past couple of days, if I m sitting in the drive thru or just idling, the rpms will drop, almost cut off and then idle back up normal.

Any suggestions? I know I need the exhaust manifold fixed, would that cause any of this?

 

Finally the dang check engine light came on. The code it pulled was a P1495 which is the pump solenoid. WTH is the 'pump solenoid'? I ve searched the site and didnt get any information.

Search on google doesnt pull up much info either. Any help is appreciated.

 

good evening everyone I'm new to the forum wrote from Rome (Italy) I have a question: is it possible to mount a manual ax 15 gc on a 4000? If you can, what should I arises to change? Hello Mister X

 

If I had to guess, and this is only a guess, I'd think it was... well, I was going to say the relay in the fuse box that runs the fuel pump. A 'pump solenoid'... that's got me, unless the book you are looking at is referring to the pump relay as a solenoid (which can happen sometimes).

It would make sense if the relay was acting up, intermittantly giving it gas pressure, which would mess with fuel supply and cause idle problems.

Maybe I should check mine, as I'm having a similar problem, except when it's started warm, not cold.

The "good thing" is that I don't believe there are too many 'pumps' in a grand cherokee... which narrows it down I think. Fuel pump is the only one that comes to mind (the oil system is all mechanical, and has no solenoid or valve I'm aware of, at least on my 94)

 

Heres what it says:

P1495 Evap leak detection pump solenoid circuit condition

-Detected the pump solenoid did not change when activated
-probable cause
-pump solenoid defective
- open or shorted circuit condition
-ecm defective

So its something in the emissions ??

 

i have really strange idle problems to, i looked at a couple other threads and i think its a grand cherokee "thing"

 

Nobody knows where this pump is?

Its not a common idle problem, mine is stalling to the point that it wants to die. RPMs drop from 800ish to bout 300ish.

If it hadnt thrown the code I wouldve thought IAC or TPS.

 

 

The manual states that the leak detection pump (if equipped) is located under the air filter housing.

 

Could this be it? Anyone ever replace one? I know where its at and not hard to get to.

http://www.autozone.com/autozone/par.../N-j9ko9Z9ixxi

 

That's the solenoid, though it's pictured upside-down. Mine's on the driver's inner fender between the washer fluid reservoir and the air filter housing.

 

Is it possible to clean it or is it one of those things when it goes bad, its just bad?

 

mine idles at 250 or at 1500 never in the middle. i had it once that when i would stop at a stop light, it would completely die, so i replaced the crank positon sensor, and it was done.

but i never had it throw me that code

 

evap codes rarely cause a drivabilty issue. The IAC, if dirty,wil not throw a code, but makeit idle weird. Also, a cracked exhaust manifold, MIGHT cause it to run wierd cause the o2 sensor is trying to compisate for a lean condiditon. I would clean the TB good, and clean the IAC good, disconnect the batt, and short the neg n positive together to reset, and see if that helps, free and easy.

 

evap sensors will usually not cause such drivability problems. on my previous car, nissan pathfinder has 4 evap system related sensors with a nice black charcoal filled canister(with lost charcoal of course) and some of sensors were broken and almost impossible to find here. i drove that car for 45000 miles until i sold it with a check engine light on, but this was not hurting idling, performance or fuel economy.(i was also using LPG system)

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i have an idle problem,also i have a little crack on exhaust manifold either. no check engine lights at all. performance and fuel economy is ok. i wonder if a new manifold cures this.