Skunkape

Started it up this morning to go to work and it was idling a little high,around 1500 rpm usually its a little under 1000.even after running about 15 min and stopping for a RedBull it stll didn't kick down.I am at work so I can't really check it out now but any ideas what to look for?kick down cable was recently adj

Diesel

IAC

Skunkape

Cool thanks,is there a way to check it?or just go ahead and replace it?Cost?

Diesel

There is no definite check, people try to clean them but 90% of the time you ruin it, its very delicate when it comes to liquid. $40

troy fritz

Check the IAC and TPS.Try cleanning them both.If you clean the IAC and it ruins it then it's not a big deal if it was bad any way.Also adjust the TPS.When you take it off there is a bullit looking thing inside,turn it a little one way and see what that does.If it runs better ,great.If not,turn it the other way.

Diesel

TPS does not control RPMs at idle. Only when pressure is put on the throttle cable, also TPS would not make RPMs run high when accelerating, only decrease response or rough accel.

troy fritz

When my TPS on my 96 went bad I had a high idle.When it got real bad I had an idle of 3 to 3500 rpms.

Skunkape

Any down side to cleaning and adjusting the tps first?If I adjust the tps first and its the iac that's bad( which sounds likely)what then?just readjust the tps to like it was?

Diesel

The only way it would cause a high idle is if the range was off, it would be reading the throttle as open.

It means that it would always read it as if you were hitting the gas and it would always be trying to accelerate, TPS does not control idle, only sends info to the ecu on how far the throttle is open.



OP, you have a 97, its not adjustable, the ECU will adjust it.

superj

maybe you have a slight vacuum leak?

Diesel

Vac leak is possible, check fitting by map sensor, they like to crack.

troy fritz

He may be right about the 97s but on my 96 the TPS will affect the idle.It's called a throttle position sensor.Which means it positions the throttle to where it needs to be.Hence high or low idle.But I may be talking out of my a$#.I don't know much about Jeeps.I did fix everything on my Jeep,including replacing the motor by my self with no help for my first time.

Diesel

TPS does not adjust idle, it just sends information to ECU(on how far the throttle is open) and works in sync with the CPS to ensure the jeep gets the correct amount of fuel/air to run. Its a sending unit, it does not control anything, just send info to the computer.

troy fritz

It does send info to comp but,if it sends the wrong info then the comp is telling IAC to do the wrong thing too.So ,in a sence it's does opperate the idle.All I know is the spring in the tps was gooked up and I cleaned it and my rig ran great after wards.

Diesel

Not exactly, IAC could be doing its job while TPS is bad and vise versa