xjblue01

well while i was at the bank i left the jeep running to goto the atm came back and my idle was flickering as low as 100 rpm which has never done before . i throw it in drive and the rpm is fine i come to a stop at the light and the rpm again lowers to 100 and the engine feels like its surging or the air box is clogged and not getting enough airflow if that possible i finally get home have it in park n it still does the same flickering n surge so im clueless on what the problem is . any help is greatly appreciated hopefully tomorrow its nice and i can run it n see if i can find the problem

CattyXJ

Check your idle air control valve There are write ups on how to remove and clean it.

Xj88

X2

TSea99XJ

x3

I've been having the same issue, or at least a very similar one. Low/Surging idle while stopped in drive. Problem doesn't occur when under power, or in any non-drive gear, Park/Neutral.

Wish I could say that I've followed the write-up on how to clean the IAC, but seems to never be enough time or daylight to complete the job, and my XJ is my DD so can't leave it torn apart overnight. But I've followed every thread I've seen that has referenced idling issues, and 9/10 cleaning the IAC resolves them.

https://www.cherokeeforum.com/f30/ho...le-body-76947/

Here's the write-up for ya!

xjblue01

ya im deff gonna do that in the morning if its nice out but weird this is i just took a quick drive to the store and truck was fine idle was fine no surge at all water temp was between 40-47 i would say temp runs 210 220 the most give or take so those are normal . its weird man never had this before but will deff have to check n clean the iac
thanx guys i appreciate it

TSea99XJ

My XJ only does it intermittently, and the times it does do it, shutting it off and restarting usually clears the problem for the time being, but resolution still appears to be cleaning the IAC motor. Pretty embarrassing when you're sitting at a red light next to someone with their window down! Already sounds like a diesel, now it sounds like a dying one. I've started keeping my left foot on the brake and right foot on the gas keeping the engine idled up to around 1000 at stoplights just so I don't feel like and idiot when this happens, lol.

Agreed though, definitely weird.

xjcrazy

Mine was doing something similar as yours. I just cleaned the iac and she is purring.

Xj88

Invest in sea foam for your tb and carb cleaner for the iac

CattyXJ

X2 on Seafoam. That's never a bad idea.

Xj88

Iac is as simple as 2 screws and a plug...spray it with carbon cleaner GENTLY run it clean and out it back in...Helped my idle a ton

xjblue01

ya seafoam sounds like an idea and deff gonna clean the iac . and tsea you ever try hyper mileing with your jeep ?? works pretty good saves gas n health of truck i would say .
im usually in neutral at red lights and stop signs

TSea99XJ

Probably a dumb question, but what is hyper mileing? Maybe something I know by a different name..?

And x3 on the seafoam as well. Something I've done with previous vehicles, and will soon be doing in on the XJ as well, the whole 1/3 in fuel tank, 1/3 in crank case, and 1/3 through a vacuum line. All of the government contracts we had when I used to work at the local Mopar dealership used seafoam in every vehicle we serviced, every time it was serviced.

I did the TB/IAC clean today, just wrapped it up and took the XJ out for a spin. Immediately noticed a smoother, cleaner idle, staying right around what would be the 950rpm mark when stopped in any gear. My issue was intermittent though just like yours xjblue, so only time will really tell if this fixed the issue, but it certainly didn't hurt!

Pictures to follow.

TSea99XJ

Top of TB & IAC after removal, before cleaning. They were both pretty filthy.


Top of TB & IAC after cleaning. Didnt seem they were as dirty initially, but after I pulled all the gunk and buildup off, I realized how much crud there was caked on to them.


Bottom side of the TB before cleaning


Bottom side of the TB after cleaning


There was also some gunk built up inside the intake manifold. Sprayed some cleaner lightly inside, squeezed my hand through as best I could, and cleaned as much as possible.

CattyXJ

Did the IAC cleaning work out? Like XJ88 said, it's two small torx head bolts. Should take no more than 5 mins...

TSea99XJ

Just throwing this out there... And its not stated specifically in the IAC Cleaning write-up.

The bottom torx screw for the IAC is a huge pita to remove. I found it much easier to disconnect the other 2 sensors from the TB, remove the top torx screw from the IAC, remove the 4 TB bolts, and once the TB was free, lift it up off the intake manifold, then remove the bottom IAC torx screw, that way you're not trying to fight with the fuel rail to get to that bottom screw. (Disconnect your 3 cables that run to the throttle linkage before lifting the TB off!)