1995 jeep xj inline 6, 4.0, 200,000 k miles with original engine, transmission, transfer case
I have no idea whats causing this problem and I could use some help
This is my first project car and I have no history of working on cars lol if i messed up somewhere lmk
Ive only had it for exactly a year and have put just less than 3k miles on it
For a few months my jeep has had a slight issue where at steady rpms (i dont have a tachometer) mostly on freeways, there will be random losses in power, but nothing concerning (i can follow flow of traffic) and the solution back then was to let off the accelerator and accelerate again. It didn't really get worse. Around a month ago driving on street roads (stop and go) the car stalled but all electronics were fine. I put in park turned off and restarted and put it back in drive for another 10 feet before it happened again. this time after restarting i turned off AC and music (i thought it was electrical) and i was able to drive it home around 12 minutes. I replaced the crank position sensor (SKP idk if thats a good brand), map sensor, throttle position sensor, and IAC sensor (i had new ones ready to install for a while) After the sensor changes it stopped stalling but still had random losses in power at steady rpms.
The loss in power at steady rpms got worse to the point where I would lose power for multiple seconds on the freeway, and now it wasnt just at steady rpms but during acceleration too. I installed new fuel pressure regulator, in line one way fuel valve, a new fuel filter, and a new fuel pump ( i didnt replace the whole fuel pump assembly, just the part that connects to the strainer). I also had 4 port injectors installed but there was something wrong with them so i put the regular fuel injectors back and sent the 4 ports back to get looked at. After all this, I still have the random loss in power at steady rpms/accelerating.
Things ive done to try and fix the problem
Within the past week
-new fuel pump (old assembly)
-inline fuel check valve
-fuel pressure regulator
Within the past year (2k miles driven)
-replaced sparkplugs
-replaced sparkplug wires
-replaced cap and rotor in distributor
-upgraded alternator to 160 amps
-jeep cables engine bay cable upgrade
-NTK O2 sensor
idk if its relevant (2k miles ago)
-replaced all fluids
-new catalytic converter (installed at a shop)
-passed smog in March 24
-replaced almost all steering components
Additional Info
-when replacing the fuel injectors i resett the ecu. at first the fuel injectors ran amazingly and the problem had completely went away. after a day of driving one of the cylinders began misfiring and the problem was worsened to the point of not having power until i let go of the accelerator
-after putting old injectors back in, the car stopped misfiring and i reset ecu again.
-no codes, i dont have a obd1 reader but i did the blinking check engine thing and only got codes for battery disconnected within 50 ignitions and end of codes
-problem persists while revving in neutral
I feel like ive seen alot of similar problems on other posts, but none that ive found have the problem persist revving in neutral
if you have any questions or things I could try that could help narrow it down then id be more than happy to try and thanks for any input
I have no idea whats causing this problem and I could use some help
This is my first project car and I have no history of working on cars lol if i messed up somewhere lmk
Ive only had it for exactly a year and have put just less than 3k miles on it
For a few months my jeep has had a slight issue where at steady rpms (i dont have a tachometer) mostly on freeways, there will be random losses in power, but nothing concerning (i can follow flow of traffic) and the solution back then was to let off the accelerator and accelerate again. It didn't really get worse. Around a month ago driving on street roads (stop and go) the car stalled but all electronics were fine. I put in park turned off and restarted and put it back in drive for another 10 feet before it happened again. this time after restarting i turned off AC and music (i thought it was electrical) and i was able to drive it home around 12 minutes. I replaced the crank position sensor (SKP idk if thats a good brand), map sensor, throttle position sensor, and IAC sensor (i had new ones ready to install for a while) After the sensor changes it stopped stalling but still had random losses in power at steady rpms.
The loss in power at steady rpms got worse to the point where I would lose power for multiple seconds on the freeway, and now it wasnt just at steady rpms but during acceleration too. I installed new fuel pressure regulator, in line one way fuel valve, a new fuel filter, and a new fuel pump ( i didnt replace the whole fuel pump assembly, just the part that connects to the strainer). I also had 4 port injectors installed but there was something wrong with them so i put the regular fuel injectors back and sent the 4 ports back to get looked at. After all this, I still have the random loss in power at steady rpms/accelerating.
Things ive done to try and fix the problem
Within the past week
-new fuel pump (old assembly)
-inline fuel check valve
-fuel pressure regulator
Within the past year (2k miles driven)
-replaced sparkplugs
-replaced sparkplug wires
-replaced cap and rotor in distributor
-upgraded alternator to 160 amps
-jeep cables engine bay cable upgrade
-NTK O2 sensor
idk if its relevant (2k miles ago)
-replaced all fluids
-new catalytic converter (installed at a shop)
-passed smog in March 24
-replaced almost all steering components
Additional Info
-when replacing the fuel injectors i resett the ecu. at first the fuel injectors ran amazingly and the problem had completely went away. after a day of driving one of the cylinders began misfiring and the problem was worsened to the point of not having power until i let go of the accelerator
-after putting old injectors back in, the car stopped misfiring and i reset ecu again.
-no codes, i dont have a obd1 reader but i did the blinking check engine thing and only got codes for battery disconnected within 50 ignitions and end of codes
-problem persists while revving in neutral
I feel like ive seen alot of similar problems on other posts, but none that ive found have the problem persist revving in neutral
if you have any questions or things I could try that could help narrow it down then id be more than happy to try and thanks for any input
