89 XJ 4.0 with AW4, 140,000. I noticed the last several days that it seems to have a miss or something. It happens very quickly and I had to make sure it was not just bumps in the road. If I were to describe it, imagine a cylinder missing once 2-3 times a minute. The only thing different is that I replaced my injectors with the Foed 19# a week ago. I can not get it to do it in 1st or 2nd. It will do it in 3rd and 4th but not until you hit 2,000 rpm. If I hit the gas peddle or on acceleration from a stop, it does not miss. I do not think it is a fuel starvation issue. Any ideas? My thinking is it is electrical as it is not constant and does not do it at similar RPM's in 1st and 2nd. ANy suggestions would be welcome.
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ENgine missing at or above 2,000
- Thread starter BSD
- Start date
jldiaz
NAXJA Forum User
- Location
- Caracas, Venezuela, S.A.
See if your TPS is OK. Check the resistance at the connector: as you open the throttle, resistance should change smoothly. Any jumps, and your TPS is bad. Also check the wires from the sensor to the ECM.
(I'm assuming you've already checked your distributor wires).
(I'm assuming you've already checked your distributor wires).
8Mud
NAXJA Forum User
- Location
- Central Germany
I re-indexed my distributor which was a partial solution, found all my vacuum leaks which also helped. Problem disappeared 99% when I put in my tool box O2 sensor (good but old). Gonna get a new O2 sensor and see If it doesn´t cure the last 1% of the occasional stutter at 2000 RPM.
Imagine the crack I have in the exhaust manifold, might also be the last little bit of the occasional stutter.
Used to happen every time I slowly accelerated (lower vacumm conditions) higher gears, through the 2000 RPM band and was pretty dramatic. Also affected my top end. Motor used to crap out at around 3500, will rev way past redline now.
Seemed to be a combination of things (including the TPS adjustment 14-15% works well), but mostly the O2 sensor in mine. O2 sensor (and probably other things) was starving the fuel some near peak torque (around 2000 RPM).
Let us know what you find out, fairly common problem, with what I think are multiple or collection of causes.
Imagine the crack I have in the exhaust manifold, might also be the last little bit of the occasional stutter.
Used to happen every time I slowly accelerated (lower vacumm conditions) higher gears, through the 2000 RPM band and was pretty dramatic. Also affected my top end. Motor used to crap out at around 3500, will rev way past redline now.
Seemed to be a combination of things (including the TPS adjustment 14-15% works well), but mostly the O2 sensor in mine. O2 sensor (and probably other things) was starving the fuel some near peak torque (around 2000 RPM).
Let us know what you find out, fairly common problem, with what I think are multiple or collection of causes.
NotMatt
NAXJA Forum User
- Location
- Wenatchee, WA
8Mud said:
This guy knows what he's talking about. I've been having similar problems, thought it was the TPS adjustment, but ended up replacing the O2 sensor on his recommendation, and my Renix 4.0 runs great now... no stuttering around 2000, just goes... gas mileage is a little bit better as well. I'd recommend a new 02 sensor first if you're having these types of problems, mine only cost me about 65 bucks from the local parts store.
jldiaz
NAXJA Forum User
- Location
- Caracas, Venezuela, S.A.
Yeah. Those O2 sensors would be the next thing to check.
