Jeep Garage  - Jeep Forum

Jeep Garage - Jeep Forum (http://www.jeepgarage.org/forums.php)
-   Engine Performance/Intake/Exhaust (http://www.jeepgarage.org/f196/)
-   -   4.7 HO weird idle in park (http://www.jeepgarage.org/f196/4-7-ho-weird-idle-in-park-22834.html)

mjl2610 05-06-2011 08:52 AM

4.7 HO weird idle in park
 
When my mothers 03 4.7L is turned on 'cold' in the morning, the idle is kinda all over the place. It will randomly rev-up to 3000 and then dip to 1000 over and over again until the jeep is put into gear. Last weekend I cleaned the idle air control stepper module thing and it idled better than before it was cleaned as it had thick oily crap on it. Could I have done something to this while cleaning? Should i buy a new one? If so, where is a good place and how much are these on average? Thanks for the help in advance.

TJXJWJ 05-06-2011 10:23 AM

Re: 4.7 HO weird idle in park
 
What did you use and how did you clean it?

It is an 03...I'd replace it. I don't think they are that pricey and that's a dealer part buddy...Maybe $50? If they sell them anywhere else, don't get it. Especially if that "other place" is Autozone or Advance Auto.

Any codes/CEL?

Amelie 05-06-2011 03:13 PM

Re: 4.7 HO weird idle in park
 
@TJXJWJ: I'm diggin' that new sig pic

TJXJWJ 05-06-2011 04:06 PM

Re: 4.7 HO weird idle in park
 
Quote:

Originally Posted by Reichminister Goebbels (Post 410269)
@TJXJWJ: I'm diggin' that new sig pic

Thanks brotha...I got a little camera happy...

StoneCold 05-06-2011 04:17 PM

Re: 4.7 HO weird idle in park
 
The only damage you may have caused is if you got any carb cleaner on the rubber o ring on the IAC valve. It's probably time for a new one or, do the revs drop when you put it drive and does it go back to high revs in neutral?

Frango100 05-06-2011 05:33 PM

Re: 4.7 HO weird idle in park
 
Further to cleaning the stepper motor, did you also clean the idle air passage in the TB? This passage is getting clogged after time and need some good cleaning.
As long as you didn't turn the plunjer head of the stepper motor, not much harm can be done to it. But if both motor and air passage are clean, its probably time for a new IAC motor.

mjl2610 05-07-2011 12:00 AM

Re: 4.7 HO weird idle in park
 
Quote:

Originally Posted by TJXJWJ (Post 410124)
What did you use and how did you clean it?

It is an 03...I'd replace it. I don't think they are that pricey and that's a dealer part buddy...Maybe $50? If they sell them anywhere else, don't get it. Especially if that "other place" is Autozone or Advance Auto.

Any codes/CEL?

I used some carb cleaner and i soaked the thing, or so it seemed. I was careful not to get it inside or so i thought. There was a decent amount of caked oily crap on it and it was pretty difficult to remove. It seemed as if the carb cleaner couldn't cut it that well, but it eventually came off.

There is no cel.

Quote:

Originally Posted by StoneCold (Post 410308)
The only damage you may have caused is if you got any carb cleaner on the rubber o ring on the IAC valve. It's probably time for a new one or, do the revs drop when you put it drive and does it go back to high revs in neutral?

Yeah i am pretty sure i got the cleaner on the o ring. When the vehicle is put into gear its normal. It is probably a reasonable assumption that I screwed something up with the IAC. Cause the idle was low, crappy and always seemed like it was going to die at a stop light before I cleaned it. After cleaning it seemed to be better, more stable idle. But now a week later i get weird idle.

Quote:

Originally Posted by Frango100 (Post 410331)
Further to cleaning the stepper motor, did you also clean the idle air passage in the TB? This passage is getting clogged after time and need some good cleaning.
As long as you didn't turn the plunjer head of the stepper motor, not much harm can be done to it. But if both motor and air passage are clean, its probably time for a new IAC motor.

I tried to clean the idle air passage as best i could, although it didn't seem super dirty. When i started taking apart the TB, everything was going well but i could not disconnect the speed control connector. Well i did not really want to force it cause i didn't know exactly how to take it off. I cant remember if i turned the plunger thing but it might have been slightly on accident if anything.

StoneCold 05-07-2011 04:00 AM

Re: 4.7 HO weird idle in park
 
Try disconnecting the battery for a few minutes. IIRC this helps the PCM re learn the settings.

mjl2610 05-07-2011 09:44 AM

Re: 4.7 HO weird idle in park
 
Well I think i may be able to get the IAC for $74 from the dealer. Might just try a new one rather than messing with the old one which i may have wrecked? Any tips on removing the speed control connector?

StoneCold 05-07-2011 01:45 PM

Re: 4.7 HO weird idle in park
 
Yeah it's just two t20 Torx screws

Frango100 05-07-2011 02:03 PM

Re: 4.7 HO weird idle in park
 
Here the procedure how to remove the speed control cable;

REMOVAL - 4.7L
(1) Disconnect negative battery cable at battery.
(2) Remove air box housing from throttle body.
The accelerator cable must be partially removed to
gain access to speed control cable.
(3) Using finger pressure only, disconnect accelerator
cable connector at throttle body bellcrank pin by
pushing connector off bellcrank pin towards front of
vehicle (Fig. 2).
DO NOT try to pull connector off
perpendicular to the bellcrank pin. Connector
will be broken.

(4) Lift accelerator cable from top of cable cam
(Fig. 2).
(5) Press tab (Fig. 3) to release plastic cable mount
from bracket.
Press on tab only enough to
release cable from bracket. If tab is pressed too
much, it will be broken.
Slide plastic mount (Fig.
3) towards passenger side of vehicle to remove cable
from bracket.
(6) Using finger pressure only, disconnect speed
control cable connector at throttle body bellcrank pin
by pushing connector off bellcrank pin towards front
of vehicle (Fig. 2).
DO NOT try to pull connector
off perpendicular to the bellcrank pin. Connector
will be broken.

(7) Slide speed control cable plastic mount towards
passenger side of vehicle to remove cable from
bracket (Fig. 4).
(8) Remove servo cable from servo. Refer to Speed
Control Servo Removal/Installation.

StoneCold 05-08-2011 06:50 AM

Re: 4.7 HO weird idle in park
 
D'oh! I thought he meant the tps oops!


All times are GMT -5. The time now is 03:57 PM.

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