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High Idle Need Help

chris420

NAXJA Forum User
Location
California
I just got my Jeep out of the shop I had it in for several issues one was high idle. My idle is around 1500 when in neutral or 1000 when In drive. The shop lubricated the cable cleaned the throttle body and cleaned the Mass airflow sensor. The high idle does not happen until the engine gets heat soaked after about 3o minutes of driving in 90 degree weather. I am going to take it back to the shop tomorrow does anyone have ideas of what may be causing the high idle?
 
You don’t have a mass air flow sensor.
You need a new shop that knows what they are doing. Smoke the intake or spray to check for vacuum leaks, also the injector seals.
Verify the IAC position is correct.
Wiggle test the TPS.
Verify the throttle valve isn’t dragging.
 
You don’t have a mass air flow sensor.
You need a new shop that knows what they are doing. Smoke the intake or spray to check for vacuum leaks, also the injector seals.
Verify the IAC position is correct.
Wiggle test the TPS.
Verify the throttle valve isn’t dragging.
 
Maybe they meant MAP sensor.
 
One thing why is th idle only getting high when the engine is hot? If it were any of the issues mentioned wouldn’t be happening all the time? I just started the Jeep after having it cool down for a for 2hours and idle is at 700 rpm. I let it run for 10minutes getting it to 210 and it still idled at 700 RPM.
 
Today the high idle was back but not until the engine had been running for 45 minutes. I was driving it and it shut down. It literliy turned off around 25 mph like someone had pulled the plug. It would not start for 20 minutes. When it did start back up it was like it was being starved of gas ⛽️I had to keep turning it over while pumping the pedal and then boom it started back up. It’s at the shop now.
 
I would have to say that you need to do some data-logging to record what's happening!
 
I would have to say that you need to do some data-logging to record what's happening!

I started recording videos and have been showing them to the shop.
 
I hope we figure it out soon I hate breaking down at speed I lose power breaks and steering kind of sucks.
 
Do you think it could be the fuel pump?
 

What kind of data are you referring to?
 
The OP's profile says 2000.

Data like O2 readings, fuel trims, % throttle, map sensor readings, etc.....
 
Yes it is a 2000 so looks like I will need an OBD II reader to record the data.
 
Shop informed me that the computer had a failed code for the CSPS and idler air control valve they replaced both and will be driving it for a few days to insure nothing else pops up. They also said the computer says the Jeep should have 4 o2 sensors but it only has 2 I told them thats probably because it’s an Arizona vehicle and does not have pre cats can anyone verify my assumption is correct?
 
Federal emissions only has 2 O2 sensors, Cali emissions has 4 O2 sensors. But the PCM's and the wiring harness are different.
 
Ok so I don’t need to worry about anything then? It’s the original harness I have never changed it. Chrysler installed the same PCM for all XJ’s so it will always be looking for 4 02 sensors?
 
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