Commonly used in early fuel-injected models with single tanks, high and low-pressure fuel pumps, the single-function fuel tank is an intermediary between a low-pressure pump and a high-pressure one. The fuel tank receives fuel from the low-pressure pump and transfers it to the high pressure one then to the EFI system while the extra fuel flows back to the tank via this same fuel tank. In cases where there is an inadequate supply of fuel by the low-pressure pump, the high-pressure pump will draw gasoline from this fuel tank to sustain uninterrupted flow of gasoline to the engine. For troubleshooting, check for any fuel blockage, since servicing cannot be done on this fuel tank.