I have a 2000 jeep cherokee 4.0 4x4 I'm having some trouble but no check engine light ...the jeep at idle will rev up and down from 550 rpms to 1000 rpms until it shuts off then restarts right away with ease and now it's is doing this thing where it is lagging in power or a hesitation till you push the pedal to the floor or let off and push the pedal again when it is not doing these things it runs great.....new battery new plugs new air filter. ...bought a new crank position sensor but did not put it in yet could this be the problem
Cherokee idle problems
- Thread starter Denny76
- Start date
JPNinPA
Well-known member
Glad you got it fixed. Again buy only OEM. Sensors What was the O2 code? They do not all equal a new sensor. Sometimes there could be triggered by intake or exhaust leaks.
OK jeep is back to same issues so I cleaned the idle control valve once again it ran great again for 2 days now it's back to rough high to low idle till it stalls but starts right back up.. then when driving it holding it a steady speed or trying to accelerate too quickly it starts to hesitate and will not pull out of it unless you floor it but goes back to doing it again as soon as you let off ....but this is all randomly don't happen all the time.......the wife uses it to deliver mail(RHD) ..she drove 10 minutes this morning to work and said it hesitated all the way to work this was 7 o'clock am it set for 2 hours started delivering mail at 9:30 am never did it the rest of the day 3 pm ....was told it could be 02 sensor or cracked boot on spark plug. ....grrrrr scratching my head
Yes I cleaned the IAC and put a OEM TPS but did not clean throttle body It looks clean tho should i still clean it ? Ya I cleared all the codes and no codes since this past Thursday and the codes that was on it was throttle positioning sensor high output voltage throttle positioning sensor low input voltage and then there was throttle positioning sensor failure and then oxygen sensor that was all on last Thursday and that's the first time it's had codes for any of them things and has not put a code out sense
superj
Well-known member
when you clean the iac, you have to clean that part of the throttle body too because its full of carbon, usually. i take the whole throttle body off so i can get in that area well.
i am not sure if it will help though as your issue sounds like something more than just the idle air controller. i bet its that throttle position sensor or wiring still.
i am not sure if it will help though as your issue sounds like something more than just the idle air controller. i bet its that throttle position sensor or wiring still.
JPNinPA
Well-known member
What was your O2 code(s)?
A bad upstream o2 could cause issues. Again OEM parts work best.
A Quick check for O2 sensors is to unplug them and tie the wires up and away from the hot exhaust. Start the vehicle. Without the O2 the PCM uses stored info in a table. It also uses this table at WOT wide open throttle. And you mention not hesitating when you floor it (WOT).
A bad upstream o2 could cause issues. Again OEM parts work best.
A Quick check for O2 sensors is to unplug them and tie the wires up and away from the hot exhaust. Start the vehicle. Without the O2 the PCM uses stored info in a table. It also uses this table at WOT wide open throttle. And you mention not hesitating when you floor it (WOT).
98Chero
New member
I had a similiar problem with my 1996 4.0l engine. I ended up opening the hood and started the engine, then started jiggling wires and wire connectors. I found a wire that was almost cut into from bending excessively. The cut was so close to the connector I had to make a jumper wire from one side of the connector to the other side. While I was there I made sure all moving cables and carb linkages and carb shafts etc.. had plenty of WD-40 on them. I hope this works for you.
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