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View Full Version : Crap Idle? 4.7 V8


NHWK05
06-17-2009, 04:55 PM
So i"ve asked this question on may other forums and no one seems to have a solution for it and apparently Chrysler denies its a real.

The jeep under no common circumstances will stall out or bog down when stopping. BTW 4.7 V8.
It will happen when the engine is cold, or hot, it will happen after alot of skinny pedal driving or under normal human grandma driving. It will happen in stop and go traffic or in normal traffic.

Basically normally when i come to a stop the rpms drop like the should and stay there. Some times it will drop well below the 500 rpm mark and then bounce back up. Occasionally it will just stall out completely and die.

I talked to a very well seasoned master jeep tech at the dealership. He said that first thing they do is a reflash of the computer. (did that and it did not fix it)

Next he said it could be the torque converter is not working properly and that adding about 1/2 a qt of tranny fluid may fix the issue. ( i will try this next)

Has anyone else sxperienced this and successfully fixed it?

Please help, its really annoying and embarassing. :(

dreamer1213
06-17-2009, 05:02 PM
Hmm....my 4.7 H.O in my WJ drops to super low idle mode when coming to a stop sometimes....it drops and idles at 400 rpm's...but has never stalled...

I cleaned out the IAC chamber and motor, and still nothing..same thing...I dunno if its a glitch somewhere in the computer system, or if its the IAC motor thats actually bad...

NHWK05
06-17-2009, 05:29 PM
I was wondering about the IAC myself but everyone i have talked with the issue said they changed it and it did not fix it. Thats why i have not wasted my money on a new IAC yet.

dreamer1213
06-17-2009, 05:41 PM
Yeah...I dunno...I was thinking perhaps when I do the superchips flash that it might perk up/smooth out the idle..

NHWK05
06-17-2009, 05:44 PM
Thats the other thing that bugs me. To me even when its not acting up, the idle never feels very smooth, it feels like it has a bad idle or bad spark plugs or sumtin, almost a very little shaky, but not in the sound, or seat or anything but i only notice it when i lean my knee on the door while idling.

Dylans3960ccs
06-17-2009, 07:17 PM
it is probably the mass air-flow sensor for your case ,Hannes your on your own?.?.

baronvonhavok
06-17-2009, 08:43 PM
i seem to have the exact opposite problem. when in park or neutral, my car idle's at 1500 RPMs. i also have the 4.7, but its non-HO in a 04 WJ. the only mod i have is the K&N intake. i can't really remember when this started happening.

any ideas guys?

dreamer1213
06-18-2009, 02:55 AM
1500 rpm idle....something is wayyyyyyyyy wrong!! I'd say the throttle position sensor perhaps your case Paul. That sensor isn't sending the computer the right info...that would be my first guess..

NHWK05
06-18-2009, 04:38 AM
it is probably the mass air-flow sensor for your case ,Hannes your on your own?.?.

There is not mass air flow sensor on jeeps.

Scottina06
06-18-2009, 09:17 AM
oh my god....Dylan tries to post somewhere beside off topic.....and has no idea!!!!LOL

baronvonhavok
06-18-2009, 09:28 AM
the other thing i realized it might be on the way to work today. i have a automatic starter installed. i don't know if this has anything to do with what might be wrong, but it might help you guys think of stuff.

i want to call the stealership, but im afraid they'll give me a lot of shit for the intake and the autostart.

any opinions on my options? haha

mjl2610
06-18-2009, 09:50 AM
Possible vacuum hose issue?? I recall on my friends Jeep his high idle was due to a vacuum hose that was broken.

NHWK05
06-18-2009, 12:05 PM
I dont know, i think all the vac lines look ok to me. I have heard of so many other people with this issue on Jeepforum (barf) and Jeeps Unlimited that i dont think its my random issue. Apparently there is a TSB on it but it is just a reflash of the computer and that did not fix it.

Scottina06
06-18-2009, 12:18 PM
I never had this problem...so its hard to know what problem your having. But....did you check all the hoses routed to the throttle body? Pull your IAT sensor and check it...make sure you replace it so air flows directly over it. How many miles? Maybe new plugs? I doubt you will have this problem with the superchips and the afe

NHWK05
06-18-2009, 12:24 PM
I have 65k miles on it. I checked IAT and it looked fine but i dont really know what i am looking for. I have not done plugs yet so maybe its time for that. is it hard to do plugs on the 4.7?

I dont have a superchips, YET, just the afe. I cant afford the chip right now.

Scottina06
06-18-2009, 12:39 PM
yeah....replace the plugs every 30K miles with stock plugs...they are only like $2 each...maybe less. Anyone can do it.....I will see if i can find it in the service manual. But on the 4.7....there are no plug wires...just ignition coil towers. Unbolt those and pull straight up to access the plugs. The back ones are kinda tight and you have to remove the intake muffler(box on top of the engine that says 4.7) But its pretty easy.

NHWK05
06-18-2009, 12:41 PM
Cool, I think i will do that. My friend works at the dealership so he can get me mopar plugs.

What is the purpose of that air intake box thingy? is it removable if i extend the air intake tube? Will it make a difference?

Scottina06
06-18-2009, 12:55 PM
Cool, I think i will do that. My friend works at the dealership so he can get me mopar plugs.

What is the purpose of that air intake box thingy? is it removable if i extend the air intake tube? Will it make a difference?

its pretty much a intake noise muffler...and yes you can rremove it...i dont have one on my 4.7. but I have a different intake than you.

NHWK05
06-18-2009, 12:59 PM
its pretty much a intake noise muffler...and yes you can rremove it...i dont have one on my 4.7. but I have a different intake than you.

Hmmm, i will look in to this.

BTW, (off topic) I just noticed your the one that responded to the E brake handle on justforjeeps.com. I wanna do that to mine but i dont think the colors will look good with a khaki interior, I want to do the center console cover as well. maybe dark slate gray?

Scottina06
06-18-2009, 01:03 PM
they make the 08 handle in khaki

robpp
06-18-2009, 01:04 PM
Hmmm, i will look in to this.

BTW, (off topic) I just noticed your the one that responded to the E brake handle on justforjeeps.com. I wanna do that to mine but i dont think the colors will look good with a khaki interior, I want to do the center console cover as well. maybe dark slate gray?

For the correct Chrysler leather, contact 22elite.com

they did my center console in Med Slate gray matches my seats perfect!

NHWK05
06-18-2009, 01:08 PM
they make the 08 handle in khaki

OMFG, THEY DO? I cant find the Leather E brake handle or the center console lid in leather in Khaki any where, only slate or gray colors. Just for jeeps does not have it.

Damn there are too many things i wanna change/upgrade.

Scottina06
06-18-2009, 01:16 PM
sorry...its called light graystone and its $123 more than the dark slte

http://www.justforjeeps.com/wkembrha.html

NHWK05
06-18-2009, 01:21 PM
Yea, Thats why i think that if i got the Dark Slate Gray e brake it would look decent and then recover the center console to match since i am too cheap to pay for a brand new one.

I already re covered the stock console with vinyl but it came out like ass, i may just have my old work re do it for $100 when i get extra cash.