Cruzer_kc04

I've had the issue since I bought it about a year and half ago. But it's getting worse when I drive longer than 5 or 10 miles it starts acting up and I lose all power and when I'm on the gas it just revs up and down while my foot won't move. Until I take it off then it settles down until I try to accelerate again. Also while it does this when I slow down fast or turning will even stall it. I feel there some issue while using powering steering and while other electrical components are used when it throws those random fits and only when it's doing that, makes me think its a coil pack issue or somethingalong those lines . I could jump in it rn and drive fine until it does that. Shutting it off and starting it again fixes it for a split second and then back it goes reving up and down until i let off the gas. It did it once when I owned it a year ago and now it's just every day ik it can happen unless it's short drives I can make it. I've replaced every sensor more than 2x got the better oem parts in now. New 62mm throttle body. The only thing coming to mind would be I have a check engine light from the o2 sensors but idk if that would cause anything like that. Can't be a vacuum leak cause it's not consistent enough.

lawsoncl

Reading your symptoms, the O2 sensor or its wiring was the first thing that came to mind. Try just unplugging it and see if that changes the symptoms.

Does the reving up and down seem like it's shifting gears, or more like it's losing power? If it feels like it's inappropriately shifting or trying to start in 4th gear, that could point to a problem with the transmission solenoids. It the stalling or stumbling happens primarily when turning or braking that might point to a wiring issue, and I'd suggest wiggling the harness along the fuel injectors to the firewall to see if you can make the engine stumble. Check the vacuum line to the MAP sensor too, if that's split at the boot near the sensor, that can cause similar problems.

Cruzer_kc04

I replaced the mapp sensor hose with a homemade one and recently put in a new stock one from Mopar took me awhile to find it. But it doesn't meet like shifting at all feels like it'll go for a second and revs to 1000 then. Again foot isn't moving at all doesn't matter how much I push the pedal . Feels like it just goes in neutral and then revs to 1000 to 2500 back in fourth within half a second just up and down up and down over and over. Just feels like im reving up and down in neutral. I heard something about the torque converter and something about a lock up system im not to sure.

lawsoncl

I'm still not sure if you're describing the engine cutting out and not having power, or a shifting issue where it's not in the right gear or shifting back and forth. Cutting out and stalling as it warms up is often the crank position sensor (CPS), but that tends to not restart until it cools off if it stalls. If it's a shifting issue, check the easy stuff like the transmission fluid level and that the throttle-body cable is adjusted properly (see https://bleepinjeep.com/video/having...v-cable-first/). It could also be the throttle position sensor causing odd shifting and the torque converter unlocking, but that's usually not temperature dependent.

To rule out the transmission solenoids, you can unplug the transmission computer and shift "manually" with the shifter. (1-2) should be first gear, (3) will give you third, (D) forth, and no torque converter lockup. I believe the transmission computer on a 1999 is on the drivers side under the dash above the gas pedal and looks like this:

Cruzer_kc04

Honestly I don't really know how to explain well. I can warm it up drive for 30 mins and be completely fine but I've noticed when I drive in high speeds for a long time it's then does this. Doesn't feel like I'm shifting at all. You feel a gear for a spilt split second and then loses all acceleration and let's say my foot is a quarter way down or half way down doesn't matter just starts reving up and down erratically until I let off the gas. If I floor it it just waits and jumps forward and loses all power and revs up and down erratically a tad bit slower but very violently. Only other sensor I left is the crankshaft sensor already have one just need to install it ill try everything you said. Really appreciate it. I wish I could explain better but truly it's something you have to witness yourself doesn't make any sense.

SurfcatXJ

Cruzer_kc04 Sounds like what was going on with my wife's TJ. Her jeep had a clogged catalytic converter.
Hope it's not that as it was around $1K for a replacement...

Cruzer_kc04

I thought it was that so I took it off temporarily and ran the exhaust out the back but it did it when it was on so doubtful.