Intermittent High or Surging Idle - Dodge Magnum 5.9L V8
#1
Registered User
Thread Starter
Join Date: Jun 2008
Location: La Sal, Utah
Posts: 40
Likes: 0
Received 0 Likes
on
0 Posts
Intermittent High or Surging Idle - Dodge Magnum 5.9L V8
I have a Dodge Magnum 5.9L V8 (from a 2000 Dodge Durango) that was swapped into my 2000 Jeep Wrangler TJ back in 2006. It took me a while to figure out what was specifically wrong, but about 5,000 miles ago, I suffered the dreaded plenum plate/gasket failure and got a lot of crankcase oil into the intake. I have now completed the work to pull my intake manifold and upgrade the crappy factory plenum plate with a beefy 1/4" aluminum plate from APS Precision, along with the newer design plenum plate gasket. The good news is that my 5.9 is running great now with plenty of power, no pinging, and no more repetitive P0171 "system too lean (bank 1)" fault codes.
However, I am still having an intermittent problem with a high (~2000 RPM) or surging idle about 25% of the time after the engine is up to operating temperature and I have come to a stop. I have no idea if it is the cause, however, I am wondering about the condition of the original idle air control (IAC) motor unit on the back side of my throttle body (which I carefully cleaned but did not replace). If the IAC is acting up, could that cause my intermittent high or surging idle?
If it's not the IAC, would any malfunctions with the following contribute to my intermittent idle problems?
- Intake manifold air temperature (IAT) sensor
- Throttle position sensor (TPS)
- Manifold absolute pressure (MAP) sensor
If anyone has any ideas as to what might be causing my idle issues, I would sure appreciate getting the input.
Thanks,
Don
However, I am still having an intermittent problem with a high (~2000 RPM) or surging idle about 25% of the time after the engine is up to operating temperature and I have come to a stop. I have no idea if it is the cause, however, I am wondering about the condition of the original idle air control (IAC) motor unit on the back side of my throttle body (which I carefully cleaned but did not replace). If the IAC is acting up, could that cause my intermittent high or surging idle?
If it's not the IAC, would any malfunctions with the following contribute to my intermittent idle problems?
- Intake manifold air temperature (IAT) sensor
- Throttle position sensor (TPS)
- Manifold absolute pressure (MAP) sensor
If anyone has any ideas as to what might be causing my idle issues, I would sure appreciate getting the input.
Thanks,
Don
#3
DTR Detective
IAC should cause the idle to be all over the place. My old 5.2 in 1996 would swing back and forth between 700-1200rpm's.
What about O2 sensor, every Chrysler product I've owned has started acting up around the 70k, 140k mileage mark.
What about O2 sensor, every Chrysler product I've owned has started acting up around the 70k, 140k mileage mark.
Thread
Thread Starter
Forum
Replies
Last Post
Jim Lane
1st Gen. Ram - All Topics
18
07-22-2016 07:04 AM
firesine
12 Valve Engine and Drivetrain
3
09-11-2007 07:14 PM
jmccart
3rd Gen High Performance and Accessories (5.9L Only)
6
06-12-2007 02:12 PM