Engine dies when switching tanks....

[quadracerx]

Hey Guys,

My 1988 Square Cab Dually TBI 454 has dual tanks, both tanks are at least half full. But when I switch from one tank to the other the engine dies? If I switch back to the original tank the engine starts and runs.

Also, not sure if its related but it runs rough, has a miss... I just tuned it up with all new cap, rotor, wires and plugs... Still runs rough...

Thanks again for all the help. This forum is amazing!

Steve

 

[dvdswan]

Switching valve gone bad sounds like.

 

[nvrenuf]

Could be a bad fuel pump, should have an electric pump in each tank.

 

[smoothandlow84]

When checking in tank fuel pump, also replace the sock filter on the pump. They clog really easily. Alo check that the rubber hose on the pump assembly is still connected. Sometimes these hoses come loose or split causung pump problems as well.

 

[quadracerx]

I assume that you have to drop the tank to change the fuel pump?

To clarify even though my truck is a 1988 GMC 3500 it is the "square cab style". Does this still mean each tank has an in tank fuel pump?

How many hours does it take someone of average mechanical ability to do this?

Thanks so much for your help.

Steve

 

[Camar068]

To drop the tank, about 2 hours and thats with stopping to change the music, couple "beverage" breaks provided you have a good floor jack and lets say a 2x6 piece of wood (if needed). That time does not include any massive cleaning/painting lol.