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Fuel issue????

Posted: Sat Jul 16, 2022 3:23 pm
by Stonewall83
I’m looking at a 96 Cherokee with the 318 (5.2L) engine. When this Jeep is put under load e.g going up a grade, it will act like it’s vapor locking. These have that indirect fuel injection similar to a TBI for intake so vapor locking shouldn’t happen. Once the hood is up and is allowed to sit for a short time, it fires up and goes again. This doesn’t happen when driving around town or not under a load. Gauges read normal. Not overheating and oil pressure is normal. It’s not throwing any codes that would explain this. Anyone have any ideas?

Re: Fuel issue????

Posted: Sat Jul 16, 2022 3:33 pm
by tgreese
Hi - you realize this forum does not cover those Jeeps? The last FSJ was a Grand Wagoneer and built in 1991.

If it's a 318 I would expect it to be a Grand Cherokee, since the Cherokee from that year came with the 4.2L inline 6. A '96 Grand Cherokee is a ZJ model; Jeep Forum has a ZJ Forum here - https://www.jeepforum.com/forums/zj-gra ... -forum.13/

Realize that spark problems can come and go with under-hood temperature. Maybe someone here will know about typical problems for the ZJ, but a ZJ forum might be more productive.

https://en.wikipedia.org/wiki/Jeep_Gran ... e_%28ZJ%29

Re: Fuel issue????

Posted: Mon Jul 18, 2022 7:37 am
by Stuka
Stonewall83 wrote: Sat Jul 16, 2022 3:23 pm I’m looking at a 96 Cherokee with the 318 (5.2L) engine. When this Jeep is put under load e.g going up a grade, it will act like it’s vapor locking. These have that indirect fuel injection similar to a TBI for intake so vapor locking shouldn’t happen. Once the hood is up and is allowed to sit for a short time, it fires up and goes again. This doesn’t happen when driving around town or not under a load. Gauges read normal. Not overheating and oil pressure is normal. It’s not throwing any codes that would explain this. Anyone have any ideas?
I moved this to the "Other Jeep related chat" area.

You could very well have an issue with spark. Could be an overheating coil, or even a CPS.