Jeep Garage  - Jeep Forum

Jeep Garage - Jeep Forum (http://www.jeepgarage.org/forums.php)
-   Engine Performance/Intake/Exhaust (http://www.jeepgarage.org/f183/)
-   -   Revving after start up (http://www.jeepgarage.org/f183/revving-after-start-up-46817.html)

Blackout 08-30-2012 01:51 PM

Revving after start up
 
So I got my Jeep in the beginning of summer (06 4.7 ~84,000 miles) and all the fluids have been replaced and also new spark plugs. In the last month or so, every time I start my Jeep up, it starts revving and goes north of 2,000 rpm's and then dies down, revs back up to about 2,000, goes down, then back up to right under 2. So it's fluctuating. So I usually have to sit there for 20 seconds and let it run it's course....just wondering if anyone has any idea why that may be.

dmsfun 08-30-2012 04:08 PM

Re: Revving after start up
 
I don't know the 4.7, but might be the idle air control valve, if that motor has one.

Blackout 08-30-2012 04:49 PM

Re: Revving after start up
 
Ok thanks. I looked that up on Google and some people had the same problem I have and they said cleaning the IAC did the trick. Thanks man

Laredo2006 09-02-2012 03:39 PM

Re: Revving after start up
 
Hey Blackout, I've noticed many have experienced the same thing with their WK 4.7's, please report back if you think the IAC cleaning/replacement fixes this. Thanks.

Blackout 09-02-2012 07:33 PM

Re: Revving after start up
 
Bought some cleaner today and will be cleaning the IAC tomorrow morning. I'll post if anything changes.

Duff Daddy 09-02-2012 08:23 PM

Re: Revving after start up
 
Be careful its not the most robust item. Btw look for signs of a vacuum leak

Blackout 09-03-2012 04:12 PM

Re: Revving after start up
 
So I looked online to see where the IAC valve is at, and when I took it out, it didn't look like other peoples. It didn't have the plunger look to it where I could clean it. So I cleaned what I could and then inside where it goes in. Also sprayed in the throttle body while it was running and overall thru 3 start ups, about 2 hours apart, there isn't any revving. It also seemed to run a little smoother. We'll see if this lasts. Fingers crossed

2005JGC 09-03-2012 10:42 PM

Re: Revving after start up
 
its been a long time since ive had a 4.7l IAC out, but Im pretty sure it has a plunger, you sure you didnt pull the throttle position sensor (just above the IAC)?

spyder873 09-04-2012 07:21 AM

Re: Revving after start up
 
Ours was doing this also , I ran some throttle body cleaner through and it stopped it for a few months . Now it is doing it again.
I am not overly concerned at this point, I plan on buying a ported one from Ryan soon,lol.

Blackout 09-04-2012 12:36 PM

Re: Revving after start up
 
Quote:

Originally Posted by 2005JGC (Post 678871)
its been a long time since ive had a 4.7l IAC out, but Im pretty sure it has a plunger, you sure you didnt pull the throttle position sensor (just above the IAC)?

That's why I was confused, from all the pics and replacement parts I saw online, they all had the plunger. When looking head on at the engine, it was to the right of the throttle body and closer to the top. Another thing, was that it only had 1 screw, picture online showed the IAC having 2 screws. So maybe I did the wrong thing. I'm back down at school now with no tools, so I'll have to try it again next time i'm home.


All times are GMT -5. The time now is 08:21 AM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community