Disconnect the electrical connection to relieve the system's pressure. Start the Navigator and let the engine run until it stalls from lack of gasoline. Turn off the ignition, reconnect the pump's electrical connection and disconnect the negative battery cable.
Step 2 Detach 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.
Step 3 Twist off the fuel pressure test port cap and secure a pressure gauge to the fuel pressure valve. Reconnect the negative battery cable and start the engine. The pressure gauge needs to read 45 psi when at wide open throttle. High pressure readings indicate a malfunctioning pressure regulator. Low pressure readings indicate a clogged fuel filter or a broken fuel pump.
Step 4 Cut the engine. Relieve system pressure and remove the negative battery cable again so you can safely remove the fuel filter to check for clogs.
Step 5 Loosen the filter fittings and unhook the fuel lines from the filter. Undo and remove the bracket on the fuel filter.
Step 6 Inspect the filter for clogs and replace it with a new one if necessary. If there are no clogs, the fuel delivery problem is probably a faulty fuel pump.
Answers & Comments
What is the correct fuel pressure for Aviator (after 5/2003)? Mine is reading at 30 psi at idle. thanks
Disconnect the electrical connection to relieve the system's pressure. Start the Navigator and let the engine run until it stalls from lack of gasoline. Turn off the ignition, reconnect the pump's electrical connection and disconnect the negative battery cable.
Step 2 Detach 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.
Step 3 Twist off the fuel pressure test port cap and secure a pressure gauge to the fuel pressure valve. Reconnect the negative battery cable and start the engine. The pressure gauge needs to read 45 psi when at wide open throttle. High pressure readings indicate a malfunctioning pressure regulator. Low pressure readings indicate a clogged fuel filter or a broken fuel pump.
Step 4 Cut the engine. Relieve system pressure and remove the negative battery cable again so you can safely remove the fuel filter to check for clogs.
Step 5 Loosen the filter fittings and unhook the fuel lines from the filter. Undo and remove the bracket on the fuel filter.
Step 6 Inspect the filter for clogs and replace it with a new one if necessary. If there are no clogs, the fuel delivery problem is probably a faulty fuel pump.
On my 2006 Lincoln navigator my fuel rail does not have a fuel pressure connection. Were can I plug it in.