While driving today I hit a large bump going 35 and my truck started to run rough and died. It will start and idle rough and then die when put in gear. I switched to the rear tank and it idled fine and ran in gear. What will cause it to run rough on the front tank and die in gear but run perfectly fine on the second tank?

 

Probably broke the pickup tube in the tank or the wire on the valve body that controls the selection of the tank. 460, 351, or 7.3l?

 

It's a 460.

 

I am still able to choose between both tanks. It idles normally w the rear tank, but idles poorly on the first tank. If I push the gas pedal on the first tank it stutters and is slow to respond.

 

Any other ideas?

 

Your truck has a high pressure pump in each tank. The front one may be weak. Rent a fuel pressure tester.

 

TTT anyone else?

 

Listen to RLA. That will give you an idea of whats wrong. If you don't follow the testing we tell you to do you won't get anywhere...

 

Ok appreciate it, how many psi should I see?

 

~32 at idle with the vacuum line attached to the regulator. When removed it should jump up to ~39 psi.