1997 jeep wrangler idle problems

[Jeepenstevo]

jeep idles up and down.No throttle response.Most times can let idle for 10 minutes then its ok.Even after its hot it still needs a warm up period.If you dont warm it up it has the problem.Jeep is tuned up and the throttlebody was cleaned.

 

[phatyaspen]

hey man try this...get a new distributor cap and rotor button..if that doesnt work get your throttle position sensor(tps) checked out,that solved my idle problems

 

[Bounty__Hunter]

The Idle Air Control (IAC) motor on the passenger side of the throttle body controls the idle. I suggest removing the throttle body (real easy, 4 bolts and throttle linkage) and giving it a good cleaning with carb cleaner and a tooth brush. Remove all sensors before cleaning. Clean the IAC housing (held on with 4 tamper-proof torx) real well and put everything back together. If that doesn't work, may need a new IAC or TPS.

Is your check engine light on?

 

[Jeepenstevo]

Had the jeep scanned.No codes.No check engine light comes on.Cleaned the Iac.Still the same promblem.

 

[Bounty__Hunter]

Have you checked the crank position sensor (CPS)? Make sure it's tight, a friend of mine had the bolts back out on his TJ.

Funny that the problem isn't throwing a code.

 

[jeepin916]

hey bet its tha TPS, mine did the same thing and had no check engine light for about 3 months and when the check engine light came on the TPS tooka dump and it stayed at 3000 rpm when ever i started it...

 

[XJNick]

Could be many things...

I agree with the above,

Check and/or replace the spark plugs, distributor cap & rotor, spark plug wires to insure your ignition system is in good shape.

Clean the IAC motor AND the Throttle body, including all IAC passages. Simply cleaning the IAC motor might not solve your problem

If neither of the above work, check the following in order as they can effect the IAC motor's behavior:

Throttle Position Sensor (TPS)
Coolant Temp. Sensor (CTS)
Air Conditioning Request Signal

-Nick :!:

 

[XJNick]

If neither of the above work, check the following in order as they can effect the IAC motor's behavior:

Throttle Position Sensor (TPS)
Coolant Temp. Sensor (CTS)
Air Conditioning Request Signal

Oh, and possibly the Knock Sensor.

-Nick :!:

 

[dwelty]

I just had the same problem. It was a 40 dollar part. The o2 sensor was bad. I had it under water , dried it out, then my idle would go up and down about 800rpm, for a few min. till it warmed up. I changed it and it runs great now.

 

[electrontech]

Could be many things...

I agree with the above,

Check and/or replace the spark plugs, distributor cap & rotor, spark plug wires to insure your ignition system is in good shape.

Clean the IAC motor AND the Throttle body, including all IAC passages. Simply cleaning the IAC motor might not solve your problem

If neither of the above work, check the following in order as they can effect the IAC motor's behavior:

Throttle Position Sensor (TPS)
Coolant Temp. Sensor (CTS)
Air Conditioning Request Signal

-Nick :!:

hi nick

My jeep has been hesitating like the rest here. I will try these um solutions, but i have a question on why an "air conditioning request signal" will cause a this issue, also i did notice my air conditioning unit is not plugged in. i tried to plug it in but teh pins are too corroded.
thanks in advance
Samuel

 

[Jeep21]

The Idle Air Control (IAC) motor on the passenger side of the throttle body controls the idle. I suggest removing the throttle body (real easy, 4 bolts and throttle linkage) and giving it a good cleaning with carb cleaner and a tooth brush. Remove all sensors before cleaning. Clean the IAC housing (held on with 4 tamper-proof torx) real well and put everything back together. If that doesn't work, may need a new IAC or TPS.

Is your check engine light on?

Hi Bounty__Hunter,

I have a 1997 2.5L Wrangler that I've cleaned the throttle body and replaced the IAC for a brand new one. I have also replaced the spark plugs, distributor cap and rotor along with the spark plug cables and both O2 sensors 4 times each. My problem is that when my car is idling the RPM's go down past 250 and then back up to 750 multiple times. I also get very little acceleration from it. Everything in the car is stock except the exhaust which I had done about 3 weeks ago. Whenever I hook up a computer to read the check engine light I always get the same code, P0171 and changing the upstream sensor seems to solve the problem for 2-3 days .This has been going on long before I did any changes yet nothing has improved with any of the changes either. Any tips?

 

[wwch99tj]

Hi Bounty__Hunter,

I have a 1997 2.5L Wrangler that I've cleaned the throttle body and replaced the IAC for a brand new one. I have also replaced the spark plugs, distributor cap and rotor along with the spark plug cables and both O2 sensors 4 times each. My problem is that when my car is idling the RPM's go down past 250 and then back up to 750 multiple times. I also get very little acceleration from it. Everything in the car is stock except the exhaust which I had done about 3 weeks ago. Whenever I hook up a computer to read the check engine light I always get the same code, P0171 and changing the upstream sensor seems to solve the problem for 2-3 days .This has been going on long before I did any changes yet nothing has improved with any of the changes either. Any tips?

Have you replaced the Throttle Position Sensor (TPS) they are known to go bad too.
Also check the wiring to the o2 sensor to make sure its making a good connection. What brand
O2 sensor are you using?

Sent from my DROID 2 Global

 

[Jeep21]

The brand for the O2 sensors are Bosch, the higher quality ones come without the connectors and i frankly don't know how to wire it. Could the problem be a leaking injector?

 

[wwch99tj]

Bosch sensors don't work as well with our Jeeps for some reason they like NTK brand sensors Www.rockauto.com has the best prices on them.

I'm not sure about the injector causing the problem, a bad injector usually causes a misfire
Sent from my DROID 2 Global