Need Help Fuel Related

[77GMCHS]

I have a 77 GMC C10 High Sierra it is a Dual Gas Tank. I have changed the Mechanical Fuel Pump to get it to run (it does kinda) but shuts off within a couple seconds unless being directly fed through a jerry can. So I went and bought the fuel tank splitter hoping to be able to solve the problem but I don't think it did since it won't pump gas from the right tank.

What should I do to be able to run off both tanks?

Next thing I'm planning on doing is removing both gas tanks and checking them and the floater/pump mechanism.

if anyone has any information I would appreciate it.

 

[chengny]

So I went and bought the fuel tank splitter hoping to be able to solve the problem but I don't think it did since it won't pump gas from the right tank.

What should I do to be able to run off both tanks?

So you are saying that the pump will pull out of the LH tank (and run the engine fine) but not the RH one - correct?

 

[77GMCHS]

So you are saying that the pump will pull out of the LH tank (and run the engine fine) but not the RH one - correct?

Yes but even with gas in the tank it runs for a little while.

 

[75gmck25]

Did the new fuel pump have the same number of lines as the old one? Some of them have only the feed line, but many also have a 2nd line to return fuel to the tank.

You also need to make sure the tank has either a vent cap, or has a vent line running up to an evaporative fuel canister under the hood (wiii be on driver's side , on radiator support next to the fan shroud).

For troubleshooting, take the solenoid under the truck out of the system and just connect one tank directly to the fuel line that runs to the pump. Then make sure that tank has at least 5 gallons of gas (or more).

Then go to the carburetor, and if its a Quadrajet carefully unscrew the fitting on the inlet and remove the barrel-shaped filter inside. Clean or replace the filter. If someone has also added an external inline filter, replace that also.

Bruce

 

[77GMCHS]

Did the new fuel pump have the same number of lines as the old one? Some of them have only the feed line, but many also have a 2nd line to return fuel to the tank.

You also need to make sure the tank has either a vent cap, or has a vent line running up to an evaporative fuel canister under the hood (wiii be on driver's side , on radiator support next to the fan shroud).

For troubleshooting, take the solenoid under the truck out of the system and just connect one tank directly to the fuel line that runs to the pump. Then make sure that tank has at least 5 gallons of gas (or more).

Then go to the carburetor, and if its a Quadrajet carefully unscrew the fitting on the inlet and remove the barrel-shaped filter inside. Clean or replace the filter. If someone has also added an external inline filter, replace that also.

Bruce

Yes it does. The main line goes from the pump and connects to the fuel splitter solenoid.

I will need to go over the troubleshooting you suggested as well as the vent cap and cannister.