My 1996 Jeep grand cherokee limited 5.2 litre loses power when at running temp does any one know why?

Question

When driving down the highway at running temp my jeep will start to lose power when I push down on the gas pedal. Does not do this when cold, only when running for a while 20 minutes or more. We have changed the Catalytic converter, one of the O2 sensors (the one in the catalytic converter) fuel filter, spark plugs, PCV valve, MAP, Distributor cap and rotor. Does anyone have any other ideas. At running temp also I can hear the fuel pump in the rear of the truck and when idling sometimes seems like it is surging. Could there be something wrong with it. If so is the fuel pump for the 96 interchangeable with one from 95 as we have a parts truck here but not sure if we can use that one or not. We are also wondering about timing. Is there a way to time this jeep, and if so where are the timing marks. Any answers would be greatly appreciated.

Answer 1

sound like a fuel pump issue or fuel regulator, hook up a pressure tester and drive.

Timming is controlled by the pcm.

Answer 2

I'd be buying a service manual for that vehicle especially if you plan on doing all the repairs yourself.Sounds like you might of hit the nail on the head and the gas pump might be the cause here but check the fuel pump relay try another relay in there that you know works well.I suspect the pump is in fact the same but don't forget to replace or at least clean the ground wire and the sending units wiring when working on the gas tank, in fact I'd change all the wires running to the tank on any vehicle I drive that age if working on tank.Too bad you couldn't do a gas pressure test when the vehicles cold and warmed up to compare the results bec that tell you a lot too.

Hope that helps and best of luck.By the way check the wiring to the gas pump relay too bec sometimes bad grounds to the relays cause such problems too.One way to find out for sure if the pumps are the same is to call up the dealership and ask for price and part number for both of those yrs, plus a good auto wreckers would know if their the same too but again I suspect highly that they are the same.