jeep wont idle...

[carguy3729]

ok, so after letting the jeep (1998 ZJ) sit most of the semester with little use, i tried to start it the other day to get it ready for the drive home....used my friends jeep to jump it off, jeep starts up but wont hold an idle?? this has happened before and i usually can get it in drive and drive it around till it charges but that doesnt seem the case this time......got the jeep to start and held the rpms around 3000 and took the battery cable off and jeep still runs.....do i need to 'reset' the electrical system or something?? :flamejump

[ryan86jeep]

the IAC? may be clogged
its one of the "valves" thatare in the throttle body, if they get gumed open they will let more air in and cause a high idle

get some carb clean, and spray down every port and open hole you can find inside of your throttle body

[nitrox28]

Sounds right. Replace the IAC, TPS, and run some Seafoam through it. $50 in parts and you can do everything inside of 45 minutes.

[MRfire]

Clean throttle body or could need new battery. I had this issue and after replacing battery all was good........

[carguy3729]

ah, well im pretty sure its not the battery cause i just had it replaced the beginning of summer....how easy is it to clean the IAC?, limited funds, limited time, and very limited tools....man, just cant wait to get this thing back to columbus so i can get rid of it....

[Bobelmore]

Likely the battery just needs a good charge.

Consensus is to never disconnect the battery with engine running -though I don't know the specific harm this could cause.

[WIJeepGuy]

If the Jeep has sat for a long time and the battery has discharged, you may need to feather the gas for a bit until the sensors readjust themselves.

You may also want to look at the possibility of tainted gas from sitting. Maybe put another 5 gallons of premium in it to dilute any nasties.

In any event, it's never a good idea to make the alternator charge a completelty dead battery. It can lead to premature alternator failure. Take the battery out and take it to a Batteries Plus store near you. They will recharge it for you for $5.

HTH,

Shane

[ryan86jeep]

have the jeep jumped for like 10 min the other vehicle running
start your jeep
let them both run

that should charge the battery up
turn it off
clean the sensors, real easy most of the time you can clean them enough just by spraying carb clean in them

do this
then start the jeep

if it wont turn over, your battery is prob dead

take it inside and trickle charge the thing for a day
then take it out to the jeep and try to start it again
let it run for a while
let it sit for an hour then try to start it again

if you have issuesstarting, the battery is dead

[carguy3729]

ok, well after keeping the thing running for a 10 min or so, i got the thing running ok and out on the road for a little test drive.....new problem...used to have a 3.5 RE lift on and have had the DEATH WOBBLe a few times but took the lift off over the summer...was drivin ok but on the test drive today it suddenly shuttered around 40 mph, and then it sounded like the rear tires were chirping/ dragging/shuttering? as well at it felt like the rear end was moving to the right??? mabye like something was binding/sticking in the rear end? very hard to explain what it was doing but now im stuck without a plan ahhh, gotta go selll some books but them im going to try and jack it up and check it out (wishful thinking) could this be something as simple as the crappy half way bald tires i got on it??

[carguy3729]

btt

[Moparboy72]

Wow, the same thing happened to me yesterday, when I tried to start my 96 ZJ, I mean it was six degrees out. ( It turned over on it's own but very slowly; no concern) The thing would not idle to save it's life though. I had about 1/8 of a tank of gas left. I was able to get it to run with my foot on the pedal and I made it run until it was warmed up---then it fixed it self. Before it would idle on its own I checked for any CEL codes but none were stored. After my Jp was running well, I went and fully topped off the gas tank as a precaution for water in the gas.
Frozen IAC?
Will a bad IAC throw a code? I know they are only $38...

[carguy3729]

btt

[Bobelmore]

Originally Posted by Moparboy72

Frozen IAC?
Will a bad IAC throw a code? I know they are only $38...

IAC will not throw a code. If giving it a little throttle cured it then imo you have a good guess. But if the IAC works after warming, I'd clean it before replacement. <30min job to remove TB and IAC for cleaning at the cost of a new TB gasket, carb cleaner & buying wife a new toothbrush ($4 total).