Rough idle help
#1
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Join Date: Mar 2014
Location: Rexburg ID
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Year: 1999
Model: Cherokee
Engine: I6
Rough idle help
I have a 99 xj with 281,000 miles on it, I'm trying to correct the rough idle and when coming to a stop then pressing on the gas to go again sometimes it almost dies. Also the start is horrible, I have to really crank it to get it to start. Most times it will stat but it has really low RPMS for a couple of seconds and then it shoots up to about the 1 mark. I tried priming it by turning the key several times but that doesn't seem to help. The check engine light is on and it has the PO304 code and PO172. Which I think means misfire in cylinder 4 and that its running rich. I just switched the spark plug from cylinder 4 to cylinder 3 today. I'll keep an eye on the code to see if it switches. Also while looking at the spark plugs it looked like the one on #4 had a smaller gap so I raised it a little.
Work done:
Injectors
cap rotor and spark plug wires
spark plugs
seafoam
Ignition Coil
Any suggestions would be great thank you!!
Work done:
Injectors
cap rotor and spark plug wires
spark plugs
seafoam
Ignition Coil
Any suggestions would be great thank you!!
#2
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Join Date: Dec 2015
Location: PA
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Year: 1997
Model: Cherokee
Engine: 4.0L
Does the fuel pump prime everytime? Check the fuel pressure and look for any vacuum leaks. Check the battery voltage. Clean the IAC and throttle body. Could even be a failing TPS, injector, or a cat thats starting to go. Diagnose what you can.
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jmrec100
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
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03-13-2019 05:42 PM
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