My 96 5.0 f250 has the dual tanks with separate pumps obviously and is only getting 15psi at the rail on both tanks and running like hell and dies. This thing came from Nevada with 124k on it and is spotless for a utility truck. I’ve checked the inertia switch, fuses,relays,grounds. You can hear both tanks kick on and run. The front tank is extremely loud when it primes and after it is fired up. I’ve replaced the selector switch, fuel filter and pressure regulator.

I believe my next step is the front fuel pump, but can one pump cause both to have low pressure and run terribly?

 

No experience with dual tanks, but offhand would consider lightly 'pinching' the return line off the rail with vise-grips or similar, to see whether the pressure changed, then would investigate whether the selector valve is doing as it should.

Not clear on your description of both tanks kicking on - would think it should be one or the other, but not both at the same time? In that line, don't see how one pump could affect the other, unless something else ain't right.

Good luck and keep us posted.

 

STOP replacing part$ until you KNOW what's wrong. How exactly did you "check" the switch, fuses, relays, & grounds? Exactly which grounds did you check? There are a bunch, and most are NOT easy to find.

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