Vinedel3

I have a 2000 cherokee 4.0 automatic, CEL was on for code p1494 (leak detection pump pressure switch or mechanical fault) mechanic told me driveability wouldn't be an issue. Recently it started idling rough when stopped at red lights and after a day or two progressed to stalling out occasionally when stopped or slowing to a stop. After it stalls it won't restart unless i let it sit for roughly 30 min. Starts fine every morning and after work but twice I've taken trips to the store (1-2 miles) and it wont start a few minutes later, unless i let it sit for more time. When mechanic read the new code he told me my coils were bad, something about B & C gap, and cylinder #4 was constantly misfiring. I replaced the coil rail and for a day the CEL went off (i assume bc i disconnected the battery) and it drove perfectly. The next day i got to work (2-3 miles) with no issue but coming back for lunch it died while stopped at sign but had no rough idle and same thing trying to go back to work. Code P1494 popped again while the truck seemed to be running fine. Truck has mostly sat since then, hasnt stalled again yet when i take it around the block to see if it will act up again.
Any help is greatly appreciated. I have a pretty good general knowledge of how an engine works but diagnosing and repair are still new to me. I just moved so i don't have anyone to trust with this, so even if i cant do it myself I'll at least know i wont be bamboozled

jeepxj99

If I had to guess, which I am, the 494 code has nothing to do with the stalls. The code seems to be dealing with the evap system which should not cause the stall. Have you checked the Crankshaft Position Sensor? These are common to have issues in the XJs. My 99 had an issue with it at about 140k miles. The issue started as I would be driving down the highway and all of sudden i had no throttle response and would just slow down to a stop. Sometimes it would cut off, sometimes it wouldn't. As the issue persisted, it became worse to the point it would cut off. Wouldn't restart for a few minutes, then may start or not. If replacing, replace with Mopar part, as it communicates directly with the computer. Have read about problems with signals on aftermarket CPS.

Additional note: CPS threw no CELs ever during the whole problem.

CompleteCherokee

let it heat up in the driveway for a while, and after at operating temp let it run for a half hour or so. Shut it down and see if it will restart. Try to get it to repeat the problem and note the conditions.

jeepxj99

x2 on this.

Does anyone know if the coolant temperature sensor could cause the start issue? I'm thinking the computer will stop the start as a fail safe if the coolant temperature sensor is reading overheated.