XJ_DR1F73R
NAXJA Forum User
- Location
- Tennessee
Okay so despite having read about a thousand threads on here for various issues in the past I am now officially a member of 
. That said, bear with me while I figure this threat posting stuff out. Now onto the fun stuff..
The back story: I have a '96 manual 4-door that I picked up a few months ago with 264K on the clock. (claimed 80K on the motor) Shortly after getting it the fuel pump gave up on me. After reading and reading I narrowed it down to either the pump or the ECM. A buddy of mine just happened to have an extra '96 ECM so I swapped it in and put a new fuel pump in at the same time.
The issue: Runs fine, idles good, pulls pretty good for being on 35's. However while driving if I downshift to engine brake -cause XJ's have AWESOME brakes to begine with lol- then hit the clutch the engine will drop to about 200rpm (the first line above zero on the tach) and sit there. It'll stay there still running for a few seconds then jump back to 1K or so before settling out to normal. During all this if I just tap the accelerator, it'll do its 1K jump and settle out. Occasionally it'll stall out completely. I've tried being every variation I can think of, from an aggressive high rev to being very mild with it to figure out at what point it becomes too much and stalls, but it's all ways the same result.
The only thing I can think of is that the ECM or some other sensor is getting confused by the engine going lean. Either way it didn't start doing it until the ECM/pump swap.
Sorry for the long post, trying to be thorough. Thanks in advance for any thoughts or advice.
. That said, bear with me while I figure this threat posting stuff out. Now onto the fun stuff..The back story: I have a '96 manual 4-door that I picked up a few months ago with 264K on the clock. (claimed 80K on the motor) Shortly after getting it the fuel pump gave up on me. After reading and reading I narrowed it down to either the pump or the ECM. A buddy of mine just happened to have an extra '96 ECM so I swapped it in and put a new fuel pump in at the same time.
The issue: Runs fine, idles good, pulls pretty good for being on 35's. However while driving if I downshift to engine brake -cause XJ's have AWESOME brakes to begine with lol- then hit the clutch the engine will drop to about 200rpm (the first line above zero on the tach) and sit there. It'll stay there still running for a few seconds then jump back to 1K or so before settling out to normal. During all this if I just tap the accelerator, it'll do its 1K jump and settle out. Occasionally it'll stall out completely. I've tried being every variation I can think of, from an aggressive high rev to being very mild with it to figure out at what point it becomes too much and stalls, but it's all ways the same result.
The only thing I can think of is that the ECM or some other sensor is getting confused by the engine going lean. Either way it didn't start doing it until the ECM/pump swap.
Sorry for the long post, trying to be thorough. Thanks in advance for any thoughts or advice.
