Got a miss like I have water in fuel but I know there isn't any water
05-09-2019, 04:11 PM
#1
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Model: Cherokee (XJ)
Got a miss like I have water in fuel but I know there isn't any water
I have a 1990 Jeep Cherokee have a miss from idle to 1800 rpms now if I stand in her it goes away I've changed fuel filter twice cleaned tank nothing major in it I'm completely lost on what's my next step
05-09-2019, 05:49 PM
#2
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I’m going to guess you’re “old school”. Have you checked the actual fuel pressure ? Spark at each cylinder while the misfire occurs ?
05-09-2019, 07:36 PM
#3
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Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
Your next step is to start testing, instead of firing the parts cannon. Start with the basics - cap, rotor, wires, plugs. Then the fuel pressure. You can rent a fuel pressure gauge from Autozone or Advance, for free. You pay for it, you bring it back, you get a full refund. They rent most tools that way.
If that's in spec, test the O2 sensor. After that, the Crank Position Sensor, then the Cam Position Sensor.
If that's in spec, test the O2 sensor. After that, the Crank Position Sensor, then the Cam Position Sensor.
05-09-2019, 11:38 PM
#4
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Misfires that go away at full throttle can be an indication of a failed/failing O2 sensor. If it is failing, the mixture will be wrong during most driving conditions, but when you go full throttle the computer ignores the O2 sensor and uses pre-canned values.
Crankshaft Position Sensor can have similar symptoms, but they don't normally go away when giving it full throttle. Typically, they have a reputation for causing even more misfires as the RPMs increase.
Crankshaft Position Sensor can have similar symptoms, but they don't normally go away when giving it full throttle. Typically, they have a reputation for causing even more misfires as the RPMs increase.
05-11-2019, 06:48 AM
#5
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Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
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