2000GMC2500

Hi, I just replaced the fuel tank on my 2000 GMC 2500. The truck has the GM 6.5. The truck ran great before I dropped and replaced the tank. I know the PMD is good so this isn't the case this time.. For some reason the truck will only run for 20-30 seconds then die. I'm pretty sure there is no air in the lines. I tried to start it for over an hour. I would crank and crank and crank it, then it would finally start, then start to cough and choke and die 30 seconds later... When I crack the fuel filter release valve on top of the fuel filter, it used to shoot out in a stream before I changed the tank.. but since i changed the tank, it barely fills up, it just trickles into the fuel filter reservoir.. if i crack the valve and crank, no fuel even shoots out of it.. So i took the fuel filter out and cranked it to see if the reservoir would fill up with diesel, but it only slowly trickles full of fuel. So.. the truck only runs until the reservoir empties, and then it dies. I am about to drop the tank and check the hoses... but I am almost positive they are hooked up right, Please help me out if anyone might know the solution my truck is siting dead in the water... Thank You. Jason

buckied

It sounds like you've got a hose pinched or something of that nature... I've never worked on a truck like you're talking about but that's the first thing that comes to mind

wannadiesel

What happens if you just turn the key on? The lift pump on that truck should run for a few seconds.

The lift pump is supposed to run off an oil pressure switch up behind the filter, make sure it's plugged in and working. What may be happening isthat the lift pump primes the system while you wait for the glow plugs, but the oil pressure switch is not taking over once the engine fires - so the truck dies.

2000GMC2500

The lift pump goes off when you thurn the key, it makes the rapid thumping sound..

wannadiesel

Yeah, how's the flow into the filter housing while the pump is running? If you have good flow, replace the OP switch...

2000GMC2500

It barley flows into the filter housing, it trickles the fuel in.... and slowly fills up..

wannadiesel

You must have something hooked up something wrong or pinched a line. Are you using the same fuel pickup as before?

2000GMC2500

yup