So i have an 88 cherokee base with ax15 manual tranny with the 4.0 inline 6. Starts fine but when I'm driving then it cuts out and essentially puts me in limp mode between 1500 and 2500 rpms. I replaced the CPS and it is still doing it. Don't have the money to go slapping new parts on it u til I figure out what is wrong. And I don't have a code reader port on it. And I'm not even sure if the CEL works on it. Any ideas?

 

What exactly do you mean by "cuts out"? Does the engine die out? Only between 1500 and 2500 rpm? So it runs OK if you keep the revs under 1500?

You can start here:

https://cruiser54.com/?page_id=75

Do tips 1-5 for starters.

Technically, there is no "limp mode". The ECU does not store codes. There is no CEL. There is a diagnostics port in the engine bay but you need a special scanner to read what's happening (DRB-III or Snapon MT2500 with the right cartridge and connector, or a Nickintime Renix Engine monitor, all expensive)). However, you can diagnose sensor issues with a multimeter. There is a Maintenance Timer that lights a light on the dash to "remind" you to change the O2 sensor and perform other emissions related maintenance. It serves no other purpose and it will run fine without it.

Did you just buy this XJ?