I have a jeep grand Cherokee limited with a 5.2v8 it ran fine until I parked it for a couple of hours when I got back and tried to start it I thought that the battery had just died but when we tried jumping it it would just crank so first guess was fuel filter well we took it to a mechanics shop and they did a full turn up replaced the coil and also replaced the cps sensor and yet it will still not start they tried spraying starter fluid directly into the intake and yet it will still not start and it has spark