Residual Pressure & Internal Leak Testing

Run engine and check fuel pressures as described previously. Turn engine off and check residual pressure. Pressure should slowly drop below 41 psi (2.9 kg/cm² ), which is pressure required to open fuel injectors. If pressure drops rapidly to zero psi, replace check valve on fuel pump.
If pressure drops slowly to zero psi, disconnect fuel return line at diaphragm pressure regulator. There should be no flow of fuel, although slight seepage is acceptable. Plug return line IMMEDIATELY if fuel flows heavily.
Pinch leak line at fuel accumulator. If pressure holds with line pinched, replace fuel accumulator. If no leaks have been found, remove cold start valve from manifold and check it for leaks under pressure. Replace valve if it leaks.
Disconnect pressure gauge and clean up any spilled fuel. Reconnect all fuel lines and run engine. Visually check all connections and lines for leaks.