How to Check for Fuel Delivery in a Pontiac Grand Am
- 1). Relieve system pressure. Loosen the gas cap to allow pressure to escape. In Grand Am models manufactured in 1990 or earlier detach the fuse connected to the fuel pump. In models manufactured in 1991 and later, detach the electrical connection to the fuel pump. Raise the vehicle if necessary. Start the engine and let it run until it stalls. Turn the ignition off and disconnect the negative battery cable. In models manufactured in 1991 and later, reattach the electrical connection to the fuel pump.
- 2). Disconnect the fuel pressure sensor vacuum hose. Check for fuel in the line. If there is fuel present in the line, the fuel delivery problem is likely caused by a faulty fuel pump pressure regulator. If there is no fuel in the line, reattach the vacuum hose and continue with the fuel delivery diagnostic.
- 3). Twist off the fuel pressure test port cap and attach a pressure gauge to the fuel pressure valve if one is not already connected. Reconnect the negative battery cable and turn the key to the first position. Do not start the engine. Check the gauge. It needs to register approximately 39 psi. Start the engine and let it idle. Check the gauge again. It needs to register approximately 42 psi. Pressure that's too high indicates a malfunctioning pressure regulator. Low pressure indicates a clogged fuel filter or a broken fuel pump that needs to be replaced.
- 4). Cut the engine, relieve system pressure again and remove the negative battery cable.
- 5). Raise the Pontiac Grand Am and use a 16mm or 20mm wrench to disconnect the fuel lines and disengage the filter fitting. Remove the fuel filter from its holding bracket.
- 6). Examine the filter for clogs and replace it if necessary. If there are no clogs, the fuel delivery problem is probably caused by a breakdown in the fuel pump itself.
Source...