evan1395
NAXJA Forum User
- Location
- Paradise, CA
So my ZJ has burned down a few weeks ago. Tranny line blew and hit the hot exhaust. Went up like a roman candle. Its ok, I have always wanted a 5 speed 4.0 XJ anyway...AND I FOUND ONE!!!
Just picked this up a couple weeks ago. 1997, 4.0/AX15. 197k miles and runs amazing. Made the 50 mile trip home from the sellers house just fine. Drove it around town for a bit and noticed a fairly bad misfire about the first 15 minutes you drive it. Previous owner had installed new cap and rotor, copper autolite plugs, wires and ignition coil. Along with a new battery. I pulled the plugs, made sure they were gapped correctly, rerouted the plug wires, and checked the distributor for play or looseness. Everything ingition wise seems to be ok. I swapped out plugs with different ports and wires with different plugs. Even swapped around injectors....STILL has the misfire. And mind you. its still worse the first 15 minutes you drive it.
I pulled my OBD scanner out and got P0301. Misfire in cylinder 1. I checked the code prior to all this work and trouble shooting as described above. Took the XJ to my buddies shop and performed a compression test and leakdown test. The #1 cylinder was around 110-115lbs. While the other five were at a perfect 150. The leakdown test only showed 10% on the problem cylinder. So I took the jeep home and opened the hood today.
I had my jeep idling with the hood open, started messing around with the injectors, ensuring the clips and injectors were all seated properly just for the hell of it. I pushed down on the #1 injector connector and wiggled the wires a certain way and the misfire stopped. Diminished completely, GONE. I kept my hand on it for a good 20 seconds just to make sure what i had done had really stopped the misfire. I took my hand off and it immediately started back up. So i figured, id go buy a new injector pigtail and solder it on. That just HAS to be the problem. Well i went and spent the $6 on a new pigtail and it is STILL misfiring. So i got to thinking that maybe the pressure i induced on the injector, was more of a O-ring problem. Like maybe the O-ring was bad and it was sucking in air. And possibly the pressure i put on the injector just helped seat the o ring and make it stop misfiring. Sooooo, I went out and bought new O rings today, installed all 6....and im STILL getting the misfire.
I just drove to the store to grab a brewski. Again, it was misfiring terribly when cold. Made the 15 minute/5 mile round trip, pulled into my driveway and the misfire is almost non existent. The previous owner has straight piped this (no muffler, but still has a cat and 02 sensor). So the misfires and louder exhaust idle is somewhat hard to tell apart. I put my hand to the tailpipe and no suck back. Atleast not anything noticeable.
At this point i am stumped. The only thing that REALLY stopped my misfire for as long as it did...was when i had been fooling around with my #1 injector. Idk if it was the way i positioned the pigtail wires...or the way I had settled the injector itself.
Help!!!
Just picked this up a couple weeks ago. 1997, 4.0/AX15. 197k miles and runs amazing. Made the 50 mile trip home from the sellers house just fine. Drove it around town for a bit and noticed a fairly bad misfire about the first 15 minutes you drive it. Previous owner had installed new cap and rotor, copper autolite plugs, wires and ignition coil. Along with a new battery. I pulled the plugs, made sure they were gapped correctly, rerouted the plug wires, and checked the distributor for play or looseness. Everything ingition wise seems to be ok. I swapped out plugs with different ports and wires with different plugs. Even swapped around injectors....STILL has the misfire. And mind you. its still worse the first 15 minutes you drive it.
I pulled my OBD scanner out and got P0301. Misfire in cylinder 1. I checked the code prior to all this work and trouble shooting as described above. Took the XJ to my buddies shop and performed a compression test and leakdown test. The #1 cylinder was around 110-115lbs. While the other five were at a perfect 150. The leakdown test only showed 10% on the problem cylinder. So I took the jeep home and opened the hood today.
I had my jeep idling with the hood open, started messing around with the injectors, ensuring the clips and injectors were all seated properly just for the hell of it. I pushed down on the #1 injector connector and wiggled the wires a certain way and the misfire stopped. Diminished completely, GONE. I kept my hand on it for a good 20 seconds just to make sure what i had done had really stopped the misfire. I took my hand off and it immediately started back up. So i figured, id go buy a new injector pigtail and solder it on. That just HAS to be the problem. Well i went and spent the $6 on a new pigtail and it is STILL misfiring. So i got to thinking that maybe the pressure i induced on the injector, was more of a O-ring problem. Like maybe the O-ring was bad and it was sucking in air. And possibly the pressure i put on the injector just helped seat the o ring and make it stop misfiring. Sooooo, I went out and bought new O rings today, installed all 6....and im STILL getting the misfire.
I just drove to the store to grab a brewski. Again, it was misfiring terribly when cold. Made the 15 minute/5 mile round trip, pulled into my driveway and the misfire is almost non existent. The previous owner has straight piped this (no muffler, but still has a cat and 02 sensor). So the misfires and louder exhaust idle is somewhat hard to tell apart. I put my hand to the tailpipe and no suck back. Atleast not anything noticeable.
At this point i am stumped. The only thing that REALLY stopped my misfire for as long as it did...was when i had been fooling around with my #1 injector. Idk if it was the way i positioned the pigtail wires...or the way I had settled the injector itself.
Help!!!