94 Jeep Grand Fuel Problems

[Okjeep]

I have a 94 Grand Cherokee and the other day when I went to drive it when I got up around 40 miles an hour or over 2000 rpm it started loosing pwr and cutting out. Then it just died and would start. Then next day I checked for spark and knocked on the gas tank and could hear the fuel pump and it starts up and runs great. Then this morning I get it and it's doing the same thing all over again. I unhooked the fuel line at the filter and turned the key on and I get gas for a few seconds, but it only does this about every 2-3 times that I turn the key on. Shouldn't it run everytime the key is turned on? I hooked up a new pump and it's doing the same thing running every other time the key is turned on. So any ideas would be greatly appreciated. Thanks!!!

[bigtim]

Hi there, I would like to give you an answer but unfortunatley my car has packed up The other day I tried starting the car and nothing, the engine cranks ok but doesn't start. After some investigation I determined that the fuel pump was shot (there is a valve on the fuel rail you can use to check fuel pressure) there was no humming of the pump when cranking the car over either.
I would be interested to know what the answer is to your question, and if you or anyone else out there can tell me how loud the pump is when running, is it a significant noise or could it be missed if there was noisey traffic about?
Sorry I can't help you and I hope you find the answer soon

Tim

[Dale Aeppli]

Originally Posted by Okjeep

I have a 94 Grand Cherokee and the other day when I went to drive it when I got up around 40 miles an hour or over 2000 rpm it started loosing pwr and cutting out. Then it just died and would start. Then next day I checked for spark and knocked on the gas tank and could hear the fuel pump and it starts up and runs great. Then this morning I get it and it's doing the same thing all over again. I unhooked the fuel line at the filter and turned the key on and I get gas for a few seconds, but it only does this about every 2-3 times that I turn the key on. Shouldn't it run everytime the key is turned on? I hooked up a new pump and it's doing the same thing running every other time the key is turned on. So any ideas would be greatly appreciated. Thanks!!!

The fuel pump only runs a few seconds when you turn the key on. This primes the fuel rail so it will start. Are you running the new pump and pumping gas with it. DON'T RUN THE PUMP UNLESS IT IS IN THE TANK WITH FUEL ENOUGH TO PUMP. The fuel cools the pump so it doesn't burn up. The pump doesn't run all the time unless the vehicle is running. hope this helps DALE [email protected]

[Okjeep]

Originally Posted by Dale Aeppli

The fuel pump only runs a few seconds when you turn the key on. This primes the fuel rail so it will start. Are you running the new pump and pumping gas with it. DON'T RUN THE PUMP UNLESS IT IS IN THE TANK WITH FUEL ENOUGH TO PUMP. The fuel cools the pump so it doesn't burn up. The pump doesn't run all the time unless the vehicle is running. hope this helps DALE [email protected]

Thanks for the help. Can you tell me a good way to test or tell if its the pump. I go out tonight to work on it again and it runs fine for about 5 min as I'm driving it around and then starts again to lose power at about 30 miles per hour and now it won't start. I checked for spark with a screwdiver connected to the coil wire and get good spark. And I have some pressure at the fuel rail but I'm not sure if it's enough. Also when I press in on the check port on the fuel rail it seems to be a little more air then fuel. I also had someone turn the key and know I can't hear any noise from the tank.

Thanks,
Kevin

[Dale Aeppli]

Can you hear the fuel pump relay under the hood click when you turn key on. Have you changed the fuel filter lately. Have someone check the fuel pressure with a gauge best way dale
[email protected] pressure should be around 39lbs.

[Okjeep]

Originally Posted by Dale Aeppli

Can you hear the fuel pump relay under the hood click when you turn key on. Have you changed the fuel filter lately. Have someone check the fuel pressure with a gauge best way dale
[email protected]

Haven't listened to the relay but I will try that. I changed the fuel filter about 3 months ago. I am trying to track someone down with guages.
Thanks, Kevin