MisterFubar
NAXJA Forum User
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99XJ 4.0 AW4 stock everything 96k on the clock.
I was out taking my end of the work week cruise tonight and about 20 minutes into I was cruising along at about 40 mph and I gave it about 3/4 throttle and it the Jeep fell on it's face. I couldn't give it any more than about 30% throttle without it losing all power.
I've got a Scangauge II hard mounted on the dash so I starting monitoring some of the inputs. Throttle position was working as it's supposed to, MAP seemed normal, Timing seemed normal, Water temp stayed at 195-203, Intake air temp was around 105, it was running in closed loop(but went into open loop at full throttle), and I can't monitor fuel pressure with it but fuel flow seemed normal. It didn't and hasn't thrown any codes, and when I got to a friends house the cat wasn't any hotter than normal.
About 2 hours later, long enough for it to cool down, I hop in and drive off and everything seems fine. Once it got up to normal operating temp it started doing the same thing, and this time I'm almost positive I heard it backfire out of the intake. RPM doesn't seem to matter, but load does. If I keep it in a low gear I take slowly take it up to 4k or so with out any problems but as soon as I give it any amount of skinny pedal it falls on it's face.
I plan on tearing into it tomorrow but I figured I'd see if anyone has any advice on where to start.
I was out taking my end of the work week cruise tonight and about 20 minutes into I was cruising along at about 40 mph and I gave it about 3/4 throttle and it the Jeep fell on it's face. I couldn't give it any more than about 30% throttle without it losing all power.
I've got a Scangauge II hard mounted on the dash so I starting monitoring some of the inputs. Throttle position was working as it's supposed to, MAP seemed normal, Timing seemed normal, Water temp stayed at 195-203, Intake air temp was around 105, it was running in closed loop(but went into open loop at full throttle), and I can't monitor fuel pressure with it but fuel flow seemed normal. It didn't and hasn't thrown any codes, and when I got to a friends house the cat wasn't any hotter than normal.
About 2 hours later, long enough for it to cool down, I hop in and drive off and everything seems fine. Once it got up to normal operating temp it started doing the same thing, and this time I'm almost positive I heard it backfire out of the intake. RPM doesn't seem to matter, but load does. If I keep it in a low gear I take slowly take it up to 4k or so with out any problems but as soon as I give it any amount of skinny pedal it falls on it's face.
I plan on tearing into it tomorrow but I figured I'd see if anyone has any advice on where to start.