Check the pressure of a vehicle's fuel pump by hooking a pressure gauge to the fitting of the fuel pump, having an assistant rev the engine and checking whether the pressure matches the vehicle's specifications. Eliminat... More »

To test a vehicle's fuel pressure regulators, connect the fuel pressure gauge to the fuel rail and start the engine with the vacuum line detached, and then attach the vacuum line and observe the drop in pressure on the g... More »

Low fuel pressure results in several issues for the engine, including rough idle, poor performance and decreased fuel economy. If the pressure is too low, the engine does not start. Fuel-injected engines are especially s... More »

To test a vehicle's fuel pressure regulators, connect the fuel pressure gauge to the fuel rail and start the engine with the vacuum line detached, and then attach the vacuum line and observe the drop in pressure on the g... More »

Signs that a fuel pump is failing include a sudden sharp decrease in overall gas mileage, high car temperature and frequent related engine stalls, slower acceleration or frequent drops in speed when accelerating or going... More »

To install a fuel pressure regulator, disconnect the fuel line to the old regulator, install the gauge, and then reconnect the fuel pump to the fuse. Disconnect the battery, and install the new regulator. Before starting... More »

To check electric fuel pump pressure in a Ford F150 pickup, test the engine with starter fluid, connect a fuel pressure gauge to the Schrader valve, have a helper crank the engine, and look at the reading on the gauge. T... More »