SubcomandanteBob
NAXJA Forum User
- Location
- Oakland, CA
(3rd paragraph to skip intro)
I’ve been reading
for years, and am just getting more serious about an XJ build. I’ve been intending to join for a while now, but my latest issue has lit a fire under that. I’ve tried several searches, but of the few threads that have my precise issue, none seem to have been solved.
My Jeep a ‘97 XJ, 4.0/AX-15/NP231. I intend to create a build thread and introduction when I have more time. I’d previously had a ‘00 XJ 4.0/AW4/NP231 with a lot of work into it and moved most of it into this one.
I had a set of 24lb 12 hole injectors on the last Jeep I’ve moved over. They worked well there, as long I didn’t get too close to WOT. I installed them on the ‘97 today with adapters. After an ECU reset and a few poor man’s prime cycles it snapped right to life, with a consistent misfire. All other cylinders are firing much stronger. The stock injectors had no misfire, just very soggy response. 232k, don’t think they’d been serviced.
I’ve tracked it to cyl. 4, and it does seem to be just there. Idle does not change when #4 injector harness is removed. OBDII check confirms, one code: P0204: Injector 4 circuit. I’ve shimmed the rail to level as these injectors are a bit longer. I pulled the injectors from the intake while still on the rail and verified all fire in correct sequence. Beautiful plumes of fine mist out of all 6, none stuck open. The plugs are firing. I purchased this a few weeks ago, but distributor, wires, and plugs appear to be new. I’ve pulled the tape off the injector harness back to the larger bundle in the wire track. The insulation is clean with no damage. I can see steady pulses on the MM, but no accurate voltage reading. The resistance on all injectors is 13-13.5 ohms. Fuel pressure is 49+/-2 at idle, and does not dip when revved. This hassle was quite unexpected, it can’t have been more than an hour from hood up to driving off when I put these on the ‘00.
Tomorrow, I intend to switch injectors 1&4, and see if the error follows, stays on 4, or disappears. I am also trying to see if I can get another set in short order, there appears to be a guy selling them on eBay, shipping from San Leandro, a few minutes from me. If anyone can provide insight into how this error is determined by the ECU, or further trouble shooting advice I would greatly appreciate it! We are intending to drive this to KOH next week and I believe this is my last item to get in order.
I’ve been reading
for years, and am just getting more serious about an XJ build. I’ve been intending to join for a while now, but my latest issue has lit a fire under that. I’ve tried several searches, but of the few threads that have my precise issue, none seem to have been solved.My Jeep a ‘97 XJ, 4.0/AX-15/NP231. I intend to create a build thread and introduction when I have more time. I’d previously had a ‘00 XJ 4.0/AW4/NP231 with a lot of work into it and moved most of it into this one.
I had a set of 24lb 12 hole injectors on the last Jeep I’ve moved over. They worked well there, as long I didn’t get too close to WOT. I installed them on the ‘97 today with adapters. After an ECU reset and a few poor man’s prime cycles it snapped right to life, with a consistent misfire. All other cylinders are firing much stronger. The stock injectors had no misfire, just very soggy response. 232k, don’t think they’d been serviced.
I’ve tracked it to cyl. 4, and it does seem to be just there. Idle does not change when #4 injector harness is removed. OBDII check confirms, one code: P0204: Injector 4 circuit. I’ve shimmed the rail to level as these injectors are a bit longer. I pulled the injectors from the intake while still on the rail and verified all fire in correct sequence. Beautiful plumes of fine mist out of all 6, none stuck open. The plugs are firing. I purchased this a few weeks ago, but distributor, wires, and plugs appear to be new. I’ve pulled the tape off the injector harness back to the larger bundle in the wire track. The insulation is clean with no damage. I can see steady pulses on the MM, but no accurate voltage reading. The resistance on all injectors is 13-13.5 ohms. Fuel pressure is 49+/-2 at idle, and does not dip when revved. This hassle was quite unexpected, it can’t have been more than an hour from hood up to driving off when I put these on the ‘00.
Tomorrow, I intend to switch injectors 1&4, and see if the error follows, stays on 4, or disappears. I am also trying to see if I can get another set in short order, there appears to be a guy selling them on eBay, shipping from San Leandro, a few minutes from me. If anyone can provide insight into how this error is determined by the ECU, or further trouble shooting advice I would greatly appreciate it! We are intending to drive this to KOH next week and I believe this is my last item to get in order.
