Test 8D: Electric Fuel Pump Inlet Restriction: Purpose

This test is performed to determine if there is a restriction in fuel pump inlet. Fuel is drawn from fuel tank through primary filter (screen on fuel tank sending unit) by electric fuel pump. Pressurized fuel (approximately 45-80 psi) is supplied to secondary filter (fuel filter housing is located in "V" on top of engine) by means of electric pump and regulator valve. Regulator relieves pressure, sending fuel back to fuel tank. Only filtered fuel going through fuel filter will go to heads. A check valve is located on both heads to prevent fuel pressure spikes in fuel rail. See Figure.