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Old June 9th, 2019, 21:50
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Chris2552 Chris2552 is offline
NAXJA Forum User
Join Date: Apr 2019
Location: West Virginia
Posts: 3
Question 98 4.0L Weird idle?

I bought a 1998 Cherokee Classic recently and it's giving me one heck of a headache. The Jeep will idle for a minute, then fall flat on its face. I've replaced the O2 Sensors, IAC, tried a different ECM, plugs and wires, TPS, and the MAP Sensor. I've cleaned a ton of grounds but still no luck. When I check for codes, I get P1391, I've replaced the CPS with 2 off of other jeeps and bought a new one, still no luck. It seems like it has a really bad misfire, but goes away in the higher RPMS. I've checked the fuel pressure and did a compression test, they checked out good. Also checked for vacuum leaks, didn't find any. I've ran out of things to check
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