• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Excessive Low Idle

HttpWayne

NAXJA Forum User
Location
Auburndale, FL
The XJ shut off mid-drive and has had an excessive low idle after the engine has warmed up. When turned on cold it idles at 750~, but right around 160 on the CTS it starts to lower gradually until it's idling at that bottom bar (500?).

I'm not sure if this is indicative of an IAC problem or not. It was previously stuck shut after having sat for over a year and I had to use a lot of heat gun and PB blaster action in cycles to get it to open up. I've been driving successfully with no problems for about a week now. I just had it out the same day it stalled (before it stalled) for other reasons and it was perfectly fine (as far as visual inspections go). I'm certain I don't have vacuum problems. Usually a loose or broken vac line causes excessive high idle since unmetered air is allow in. This seems like the opposite.
 
Could you have a lack of OEM designed vacuum leaks, like the rear CCV metering line being clogged? IAT temp sensor is dirty? Low fuel pressure.
 
It's a 2000.

All OEM lines are connected, I haven't checked for clogs but I can't possibly fathom a reason I would have one in the PCV. It's only been running a week and it's a fresh rebuild.

It stopped doing it yesterday afternoon and went back to normal. I'm not sure what it was. But later on I went into the store and it sat for a while and turned on to go straight to very low idle, and it was reading very lean (18+). My gauge doesn't read past 18 so I shut it off and went to look around in the engine bay. I didn't see any disconnected lines or connector and the fuel hose was thoroughly pressurized based on feel. I started it back up and it was normal.

There usually aren't any coincidences and since it shut off just after I reconnected a water injection kit I think that had something to do with it. I hooked it back up yesterday afternoon and it locked up on my again so I disconnected it, but It didn't give me any idle problems. THe ironic thing is previously when I used it I had it connected directly to a manifold port before the supercharger and never had any problems with it. Now it's connected to the air box so it has more room to atomize and it keeps locking up. I'm beginning to wonder if it has something to do with wet sensors. That would make much sense because previously I also had it connected to the airbox at another time, and I could tell from the filter it certainly was spraying into it.
 

LOL, gotta love it, hey folks, I have a jeep with a low idle, whats wrong??????......later we get word it is a modified black box rig with god knows what else on it besides OEM stuff, like water injection and a supercharger, LOL:eek:.
 
Back
Top