Slony

I have a '96 Regular Cab 5.0L 4x4 and have had fuel delivery issues the past month. I drove home from work one evening with everything running great and parked the truck and shut it off. The next morning the truck started and ran for maybe 5 seconds and then it died. The truck would not start afterwards so I switched to the rear fuel tank. The truck started up and I continued to drive on the rear tank for the next two weeks. After running on the rear tank for about two weeks I stopped at the gas station and fuel is leaking out of the fuel cap from the front tank. I opened the cap and the fuel level was past the small filler neck flap.... Correct me if I am wrong but the bypass fuel is circulated back into the front tank which may have caused this overfilling situation?

Fuel overflowing out of the front tank only happened one time. About a week later I figured I would use a transfer pump to transfer fuel from the front tank to the rear. When I opened the front gas cap, air was released from the tank. I don't quite remember if it was belched out or sucked into the tank. So I transferred a small amount of fuel from the front to the rear. After hearing the air escape I thought I would try out the front tank again to see if maybe it worked and it did. It worked very well like nothing was wrong, for a week.....

So now I am back on the rear tank again and all is fine for about two weeks when suddenly on my way to work my truck is sputtering and about to die. The sputtering worsens as I try to accelerate or keep up speed but then suddenly is fine for another 4 miles and then sputters again.

I am leaving work now and the truck almost dies while backing out of my spot so I just out and take the gas cap off to see if the tank is pulling a vacuum. The truck ran just fine all the way home, so the tank was not able to vent itself.

At this time I am certain it is a evap system issue. Except now the truck won't start at all and the fuel pumps will not kick on when the key is turned to the on position. I check fuses and relays with no obvious issue. I have no voltage at the fuel pump fuse location with the key in the on position.

Are both of my fuel pumps bad now? My concern is that I replace both fuel pumps and then I continue to have an evap system issue.

If anyone knows of good tests for problem shooting the fuel pumps and evap system please let me know. I plan to run a resistance test on the leads to the fuel pumps to see if I have infinite resistance through the pumps to see if they are shorted out.

As far as the evap system, I have no idea how to problem shoot this. Does anyone have any good recommendations for fuel pumps? I was planning to order from LMC Truck originally.


Thanks for taking the time to read this book. Looking forward to all opinions.