To troubleshoot insufficient fuel delivery, ensure the battery is fully charged and check all fuel lines for leaks. Listen for the fuel pump operating when the ignition is switched to ON. If silent, check the fuel pump electrical circuit for a firm connection and inspect the wiring harness. If the pump runs but issues persist, perform a fuel pressure check. For V6 models, disconnect the fuel supply hose quick-connect fitting in the engine compartment's left side and connect a pressure gauge using a special fitting. For V8 models, remove the banjo bolt connecting the front fuel crossover pipe to the left fuel rail and install a special banjo bolt Schrader valve, then connect the pressure gauge hose to the adapter. Note the reading on the gauge after the fuel pump runs for about two seconds with the ignition key set to ON and the engine idling at normal operating temperature. Compare the fuel pressure with the specified value. If the pressure is too high, check for obstructions in the fuel return line or replace the
Fuel Pressure Regulator. If it's too low, pinch the fuel return line and observe the gauge. If pressure doesn't increase, replace the fuel filter or fuel pump. After the pressure check, relieve system fuel pressure, remove the adapter and pressure gauge, reconnect the fuel lines, and the battery, and check for leaks. If the pump doesn't turn on with the ignition in the ON position, check the IGN fuse, EFI fuse, circuit opening relay, EFI relay, and fuel pump relay. If relays are functional but the pump doesn't operate, inspect the fuel pump circuit connectors and wiring through the access plate on the floor.