Yes, each tank has it's own high pressure pump. In the tank itself. When you select a certain tank, that pump turns on, the other one turns off and fuel is pumped to the fuel rail atop the engine. The pump always pumps more fuel than the engine could possibly ever use, so there is a return line via a fuel pressure regulator. Each tank has it's own return.
I don't think you have a bad fuel pressure regulator, because the truck would run equally poor with either tank selected. A noisy pump is often an indication that it's going bad, though i've seen noisy pumps last years so long as the tank isn't run dry of gas. The gas in the tank cools and lubricates the pumps, run out of gas several times and the pump could burn up.
The first thing to do is check the fuel pressure at the fuel rail, while the truck is running on each pump. If you find that you have low fuel pressure while running off the front pump, then I would suspect either a bad pump, a bad check valve (which is in the pump) or an obstruction in the fuel circuit for that tank. A plugged filter would do that, however I haven't seen but one fuel filter that services both tanks in these trucks. I'd check it, or replace it if you haven't done so in a couple of years.
I know there's a way to post pics on here, but i've never been able to figure out how.
Thursday, January 3rd, 2008 AT 8:28 PM