Car Repair World

How To Test Vehicle Fuel Pump And Fuel Pressure Regulator Helpful Information Some vehicles are not designed with a fuel pressure test port, in which case a fuel filter adapter must be used for the gauge connection. A fuel pressure regulator is controlled by a diaphragm and spring combination in conjunction with intake manifold vacuum. When a fuel pressure regulator diaphragm ruptures, it allows raw fuel to enter the vacuum feed line and into the engine. This condition creates a rich  black smoke  from the tail pipe on start up and while running. Remove the vacuum line from the regulator, if fuel is present, the regulator has failed. Some GM (CPI Injection) are designed with an internal regulator in which the intake manifold must be removed to access. Most fuel pressure regulators are on the top of the fuel rail. If you cannot locate the fuel pressure regulator consult a  repair manual . Tool and Supplies Needed Fuel pressure gauge kit Protective eyewe...

How To Replace Vehicle Fuel Pump Helpful Information Some manufacturers provide an access door to service the fuel pump, be sure to research this information before beginning. To test for a fuel pump failure a  fuel system pressure test  must be performed. Sometimes the the driveshaft must be removed along with the fuel tank. The automotive engine is designed to operate on a specific fuel system pressure which is vital to  engine performance . To maintain a constant pressure, the  fuel pump  is located in the fuel tank and is comprised of an electric motor coupled to a small internal vein style pump. Fuel pumps have a pressure relief valve that allows fuel to bypass while recalculating inside the fuel tank. Direct injection fuel pumps utilize an internal pressure regulator, while having only one liquid fuel line routed to the engine as opposed to two, (pressure and return lines.) When the ignition key is turned the fuel pump relay engages while suppl...