Fuel Pump: Description

NOTE: Some vehicles were retrofitted with electrical fuel pumps to solve a driveability problem. For procedure see TSB 18-04-86 dated February 10, 1986.

Two types of fuel pumps are currently used. Most carbureted gasoline vehicles use an engine-mounted mechanical pump. Gasoline vehicles with fuel injection use an electric pump normally located in or near the fuel tank.

Some models use a low pressure electric pump in conjunction with a high pressure electric pump. Usually one pump will be located in the fuel tank, the other externally. This provides adequate fuel delivery during extreme vehicle maneuvers or steep inclines with low fuel tank levels.

Vehicle manufacturers recommend that the pump be replaced as an assembly if found defective. Check pumps for fuel pressure, volume, and vacuum (suction). DO NOT attempt to overhaul or repair pump assembly. Some pumps will have an extra connection for fuel and vapor return to aid in hot starting and prevention of vapor lock.