Fuel tank and hose help

[eherbaugh]

Here is what I have going on with my 1985 c10 with dual tanks. Truck only has the driver side tank installed. The selector valve has been bypassed. I have a mechanical fuel pump with no return. I have been having a lot of fuel fumes. So I have a charcoal canister and when looking at the fuel system I noticed the vent line under the hood is not connected to anything and the return line is capped off. When I looked at the actual tank sending unit it appears that the fuel return and vent fittings on the tank are hooked together. Why would someone do this? I assume this is part of my fuel smell issues. Any and all help would be great.

 

[bucket]

Hook the tank vent line back up so it vents through the charcoal canister. That should be a good place to start.

 

[Broken85]

Don’t waste any more time with this amalgamation the PO left you. Spend your energy switching it back to OEM and diag from there. It doesn’t sound like anything is right with that fuel system.

 

[75gmck25]

Start out by getting one tank plumbed correctly, and worry about the 2nd tank later.

A fuel pump with a return line usually works better because it keeps the fuel circulating, and therefore cooler and less likely to vapor lock. A fuel pump with return should be available from any food pests store, and it’s not expensive.

Hooking up the charcoal canister to the vent line under the hood may work, but it sounds like the PO may have removed other vacuum lines. The canister is designed to capture fumes all the time, but only vent periodically.

The venting is usually managed by a vacuum device, and it is different between 2 and 3 port canisters. Sometimes the vacuum device is built into the canister, so you just hook it up to the right carburetor port. In other years the vacuum control is separate. As an interim vacuum source you may be able to T it into your PCV hose and have it recover fumes all the time.