2001 Sonoma Flex-fuel Fuel Line Schematic?

[dave_in_az]

I'm replacing the fuel fump for a friend's 2001 Flex-fuel 2.2L Sonoma and am baffled a bit by the fuel line routing. Inside the pump, the actual pump outlet goes via flex tubing to an outlet port of the pump assembly, which connects to one input of the fuel filter. Another flexible tube inside the pump , larger than the forementioned flex tube, just appears to hang down into the pump assembly cavity from an outlet port which goes to a second (input?) port of the fuel filter. In addition, a third line goes from the pump module (check valve?) to the carbon canister, and the fuel filter itself has a third port whose line goes towards the engine (I'm assuming the fuel rail}. Hope this makes sense.

To recap, the pump module has 3 ports, 2 which go to the "input" side of the fuel filter, and 1 which heads towards the carbon canister.

Question: Why are there 3 ports on the fuel filter?

Also, a fuel line schematic would be awesome, if anyone has one. Thx

[MT-2500]

Originally Posted by dave_in_az

I'm replacing the fuel fump for a friend's 2001 Flex-fuel 2.2L Sonoma and am baffled a bit by the fuel line routing. Inside the pump, the actual pump outlet goes via flex tubing to an outlet port of the pump assembly, which connects to one input of the fuel filter. Another flexible tube inside the pump , larger than the forementioned flex tube, just appears to hang down into the pump assembly cavity from an outlet port which goes to a second (input?) port of the fuel filter. In addition, a third line goes from the pump module (check valve?) to the carbon canister, and the fuel filter itself has a third port whose line goes towards the engine (I'm assuming the fuel rail}. Hope this makes sense.

To recap, the pump module has 3 ports, 2 which go to the "input" side of the fuel filter, and 1 which heads towards the carbon canister.

Question: Why are there 3 ports on the fuel filter?


Also, a fuel line schematic would be awesome, if anyone has one. Thx

It is a new type of fuel return setup.
The fuel filters are higher priced and should be replaced with good quality fuel filters.

Instead of a fuel pressure regulator return setup.
They use a pressure return from the fuel filter on that system.

Inside the module the pressure from the pump is feed to pressure to fuel filter.

Pressure return from filter is returned back into the tank and controls fuel pressure to engine.

The vent Line from fuel tank to carbon filter or engine vents fumes/pressure from tank and some setups pull vacuum on tank.