Super Annoying Rough Idle Issue (Can't Find Info On This Anywhere)

WPGB1977 said:
I have been chasing a rough idle issue for the past couple of months and it is killing me! I have researched this issue and have exhausted all of the threads and can't really get to a solution that doesn't require deep mechanical knowledge or a relatively large amount of money.

I have thrown the usual "easy" solutions at it - new plugs, cleaned IAC and throttle body, run fuel system cleaner through it - but to no avail.

Jeep isn't throwing any codes. Here's what's going on.

Symptom #1: Will idle roughly at a standstill. Barely perceptible but definitely there. Intermittently worse some times than others. Could just learn to live with this except for Symptom #2. See below.

Symptom #2: This is what is weird. After backing the Jeep into a parking spot or my garage, it really bogs down and threatens to quit. Sounds horrible and can't be good for it. After about 15 - 20 seconds of sounding like it's struggling to keep running, it goes back to idling *almost* normally much like it does in symptom #1. By the way, the extent of the struggling varies and I can't correlate it to any specific conditions (heat, length of time running the Jeep before reversing it, etc.)

I will say that these issues don't seem to exist until after the engine warms up.

I have had 3 separate mechanics look at this and they agree they can feel it but can't get to the source of it without it getting expensive. One guy mentioned the O2 sensors which I will tackle next but I wanted to throw this out there to the community in case anyone has had a similar issue, especially if it relates to REVERSING the Jeep.

Help!

Thanks.
Click to expand...
I am having the same issues. Mine jumps around like it has jumped time then dies. It keeps blowing a P0113 code. So I replaced the IAT sensor still seconds after cranking engine light comes right back on. I replaced the 02 sensors and the air filter still having this issue. Help!!!
 
I just had this problem start today - before I even left my neighborhood I was getting intermittent loss of power without changing the pressure on the pedal - this thing was bucking. I couldn't even get enough speed to get the thing into third gear, barely enough to get it into second.

I pulled over once my CEL started flashing at the edge of my neighborhood and checked my wires - one was quite loose and had a slice in the insulation.

I had to have it towed to my mechanic who just put a new head on it, a new Wranglerfix ECM (2.4l 6 speed), cam sensor, crank sensor, throttle position sensor, coil pack and a few more things about a month ago. I drove it around 650 miles since I had this work done and haven't had any issues - it's been running better than ever until this morning.

Today he ended up doing plugs and wires and it runs but the idle is noticeably off, and it just sounds sloppy like my valves are slapping on my new head. After it's been idling for a short time (like 10 seconds) it feels like it's going to stall every few seconds but it doesn't. As I let off the clutch in both first and second gear I can feel what I would describe as hesitation in transferring power to the wheels.

After reading this thread I'm thinking maybe I should check with my mechanic about the sensors he put in it a while ago, however, I'm scratching my head because like I said - absolutely no issues for 650 miles.

I'm gonna give him a shot at diagnosing it but I may end up taking it to the Jeep specialists shop around the corner. I've spent a couple grand on this thing over the past few months and I'm really hoping this morning didn't damage my new head.

Is this Jeep life?
 
WPGB1977 said:
I have been chasing a rough idle issue for the past couple of months and it is killing me! I have researched this issue and have exhausted all of the threads and can't really get to a solution that doesn't require deep mechanical knowledge or a relatively large amount of money.

I have thrown the usual "easy" solutions at it - new plugs, cleaned IAC and throttle body, run fuel system cleaner through it - but to no avail.

Jeep isn't throwing any codes. Here's what's going on.

Symptom #1: Will idle roughly at a standstill. Barely perceptible but definitely there. Intermittently worse some times than others. Could just learn to live with this except for Symptom #2. See below.

Symptom #2: This is what is weird. After backing the Jeep into a parking spot or my garage, it really bogs down and threatens to quit. Sounds horrible and can't be good for it. After about 15 - 20 seconds of sounding like it's struggling to keep running, it goes back to idling *almost* normally much like it does in symptom #1. By the way, the extent of the struggling varies and I can't correlate it to any specific conditions (heat, length of time running the Jeep before reversing it, etc.)

I will say that these issues don't seem to exist until after the engine warms up.

I have had 3 separate mechanics look at this and they agree they can feel it but can't get to the source of it without it getting expensive. One guy mentioned the O2 sensors which I will tackle next but I wanted to throw this out there to the community in case anyone has had a similar issue, especially if it relates to REVERSING the Jeep.

Help!

Thanks.
Click to expand...
Myself, I changed plugs, wires, throttle body, and gas pedal still rough idle
WPGB1977 said:
I have been chasing a rough idle issue for the past couple of months and it is killing me! I have researched this issue and have exhausted all of the threads and can't really get to a solution that doesn't require deep mechanical knowledge or a relatively large amount of money.

I have thrown the usual "easy" solutions at it - new plugs, cleaned IAC and throttle body, run fuel system cleaner through it - but to no avail.

Jeep isn't throwing any codes. Here's what's going on.

Symptom #1: Will idle roughly at a standstill. Barely perceptible but definitely there. Intermittently worse some times than others. Could just learn to live with this except for Symptom #2. See below.

Symptom #2: This is what is weird. After backing the Jeep into a parking spot or my garage, it really bogs down and threatens to quit. Sounds horrible and can't be good for it. After about 15 - 20 seconds of sounding like it's struggling to keep running, it goes back to idling *almost* normally much like it does in symptom #1. By the way, the extent of the struggling varies and I can't correlate it to any specific conditions (heat, length of time running the Jeep before reversing it, etc.)

I will say that these issues don't seem to exist until after the engine warms up.

I have had 3 separate mechanics look at this and they agree they can feel it but can't get to the source of it without it getting expensive. One guy mentioned the O2 sensors which I will tackle next but I wanted to throw this out there to the community in case anyone has had a similar issue, especially if it relates to REVERSING the Jeep.

Help!

Thanks.
Click to expand...
 
Chris said:
Wow, sounds like you've found yourself a reputable mechanic, those are hard to find! Most of them would never charge you less when they knew they could charge you more, so clearly these guys are honest.

I also know for a FACT that if you are running an aftermarket replacement OPDA (as most of us are), the aftermarket sensors that come on them are notorious for not working properly with our TJs. For that reason, most people buy the aftermarket OPDA, but they replace the CPS sensor on it with the OE Mopar CPS sensor.

I'm actually betting that right there is a huge contributor to the issue. Hell, had I known you had an aftermarket OPDA that would have been the first thing I suggested was replacing the CPS sensor with an OE unit.

Moral of the story here is ALWAYS use OE Mopar sensors on TJs. They simply do not like aftermarket ones.
Click to expand...

Is this the jeep guys in greensboro, nc. I am in goldsboro
 
I have a 98 TJ and have the same issue, bought mine from a fella that has done almost a rebuild, under the hood. not sure if this was done but I am definitely going to find out. I have even pulled the O2 sensor before the cat thinking possible cat was plugged with over 180 miles and stock exhaust. it did seem to idle and run great. BUT... I have not tried from cold start and tested that theory either. I am going to keep following this thread also.
 
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