Fuel Return Line: Description and Operation

Fuel pipes and hoses
Fuel feed and return pipes (lines) and hoses carry fuel from the tank to the fuel rail. These pipes and hoses are attached to the underbody of the vehicle and must be inspected for kinks or dents which may restrict fuel flow.

Fuel vapor pipes and hoses carry fuel vapors from the fuel tank to the evaporative emissions canister located below the underbody. The fuel vapors are stored in the canister when the engine is not running. When the engine is running at normal operating temperature, and the accelerator pedal is depressed, the engine control module (ECM) will cause the evaporative emission solenoid purge valve to open and allow the stored fuel vapors to be purged into the intake manifold and be burned during the combustion process.