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i really dont understand why its doing this...

MaxxXJ

NAXJA Forum User
Location
Bakersfield CA
ok, its 2 possible problems but it might be the same one.

my first problem is maybe once a week i could be driving down the street in Overdrive doing anywhere between 45-60 and out of the blue my jeep will feel like i ran over something the size of 1" angle iron (but nothing is ever there)

my second problem just started recently. i was sitting at a stop light tonight and for no real reason it acted like the keys got turned off then on again. the lights dimmed the RPM's dropped and the engine dieseled but didnt die, it only happened for a split second and after that everything runs fine. so i dont know if i should just wait for something to break then fix it or troubleshoot my issue until it's resolved. i really dont want to be stranded on a trail somewhere and have something like my tps go out or cps.

if anyone could provide some knowledge on my subject. i'd greatly appriciate it, thanks.
 
ALWAYS provide the basics when asking a question: year/engine/trans (OD so its an auto)/mods/recent work done/blah/blah/blah/anything else that might be important. Thank you.
 
sorry bout that joe.
its a 2000 4.0 sport 126K miles. with the aw4 trans and np231 TC it has a 4" lift on 33x10.50's. 3.55 gears, pretty new fluids in the differentials, it has a TC drop but it's always done the kick down issue, no mod's the engine is stock. just recently smogged it and it almost didnt pass due to high hydro carbons. i changed my rear O2 sensor a year ago but not the front. i've been adding the stp fuel additive into my gas tank trying to ssqueeze every mpg i can, the cat is at least 3 years old as well as the muffler. i am running full synthetic mobil 1 oil in it. um i think thats it. if i can think of more i'll post it
 
If it was a GC or Explorer I would think the fluid coupling in transfer case was screwing up--no help to you but it was the first thing I thought of.

Rule number one Chrysler driveability issue when the vehicle is equipped with an AW4: unplug the TCU and drive it shifting manually to eliminate the trans as the source.

With the TCU unplugged you will have 1st in 1-2; 3rd in 3; 4th in D; reverse, neutral, and park. Try driving it like that for a week and see if the angle iron sensation stops presenting.

I would replace the front o2 sensor as it feeds the PCM engine management data, the rear o2 sensor is just there to rat out the front o2 sensor--kind of like a kid sister! See if replacing the o2 sensor doesn't get you some mileage back and your HC down. As for the odd running issue, start with the battery and work out from there--have the battery load tested, clean the cables, renew all of the grounds. In the meantime if it acts like it is dying again put your eyeballs on the voltmeter and see what it is doing.

Are you getting a CEL or any codes?
 
I had a 95 with an ax-15 2wd that would just die randomly and not very often this was due to some corroded wiring and a hacked wiring jobnear the fuse block.
Then again I had an 87 with an AW4 that had the same power that would come one and go off killing it while driving and killing lights, it got worse over time till one day it died and I had to tow it. Turned out to be one of the main wires feeding the igintion through the firewall connection (that damned bastard thing) had corroded so badly that the terminal fell apart when i seperated the connection. I have seen this happen to two other friends rigs up here in Alaska; we tend to get a bit of precipitation here.
 
no codes or cel, and i have a volt meter plugged into my cigg lighter adaptor, so i have a pretty constant reading. it usually reads on average between 13.85 and 13.95 and when the engine is shut off it slowly drops off from 13.2ish to 12.6 then reads a constant 12.6

the transmission issue is weird, sometimes it wants to short shift on me causing it to shift hard. the angle iron sensation also feels very similar to driving a large vehicle with clutchless shifting and when you shift too soon or out of the sweet spot and it jerks into gear. i had the transmission checked but the tech didnt find any issues. its not an everyday thing its just at random, from recent trial and error, running it in 3rd instead of OD it hasnt had the weird angle iron issue.

i will change my front O2 sensor, hopefully it will fix my 12mpg issue's.

my battery is checked pretty regularly, i clean the post's anytime i see any kind of corrosion or discoloration. i havent renewed the grounds yet but the power cables may be in my near future.

when i say it acts like it's dying, its almost like you sprayed a mist of water or something not flameable into my carb and causes it to stumble for a split second, then clear up.

i may change my cat too, it's pretty old as well as the muffler. the muffler is worn so thin that it looks like it has cancer in spots. i just need a quiet muffler thats not going to break the bank. thanks for the info joe
 
i used to have a short in my fuel pump wiring that caused it to stumble like how you are talking about.

i found it by listening carefully to the pcm, while having someone else twist the wire harness around. the pcm would squeak when the the other person's hands were close to the short. my pcm literally told me where my short was!

kinda like a woman, sometimes you just gotta slow down, listen to her wine a little, and message it a bit.
 
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