90 4.0L misses

TheZenTree

TheZenTree

Well-Known Member
Joined
Mar 20, 2005
Location
Central KY
I was out driving my XJ a few minutes ago, and I noticed that it's missing really badly between 1950-2300rpm. If it's above or below that range, it runs like a top, but for some reason, it feels like it's missing every other cylinder when it's there. Anyone got any sorta idea of what's goin on here?
 
TheZenTree said:
I was out driving my XJ a few minutes ago, and I noticed that it's missing really badly between 1950-2300rpm. If it's above or below that range, it runs like a top, but for some reason, it feels like it's missing every other cylinder when it's there. Anyone got any sorta idea of what's goin on here?
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Is it missing or not getting enough fuel?
 
I'm not sure. I'd imagine that it's missing since it's only doing it at those rpms, but I guess it could be a fuel problem.
 
maybe you should sell it and get a K5, lol jk john. i dont know what to tell you but my thunderbird did that at a certain rpm just like you were describing. mine was a coil pack. do you have a check engine light?
 
It's not on, but that doesn't mean it's not "on." I'm gonna try new ignition junk and replace the fuel filter and see where that gets me. I guess I didn't think to try that because it really only does it at certain RPMs, but hey, I'm a n00b.
 
My mother bought a brand new E150 van w/ 5.4L and she had not had it long when it started sputtering around high rpm's. It would get up to a certian speed and would not go anyfaster, lagging power. With a few runs to the dealership we found it was the fuel pump that crapped out. Luckily it was under warranty.
 
How many miles? Has it ever had a cap, rotor, plugs and wires? I had a '99 Cherokee Sport for a work vehicle that started missing at the same rpms. I took it in (work vehicle, remember) and they did a full tune up. I put another 60,000 miles on it afterwards and had no problems.
Couldn't hurt to do a tune up?!
 
No idea how many miles. I've only owned it for a few months and have put maybe 5 hours on it, but this weekend when I go home it'll get cap/rotor/wires/plugs and we'll see how that works.
 
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