If you suspect insufficient fuel delivery, first inspect all fuel lines to ensure that the problem is not simply a leak in a line. Set the parking brake and have an assistant turn the ignition switch to the ON position while you listen to the fuel pump; you should hear a whirring sound for a couple of seconds, which should become continuous when the engine starts. If there is no sound, either the fuel pump or the fuel main relay circuit is defective. Relieve the fuel pressure, remove the service bolt from the top of the service fitting on the fuel filter, and attach a fuel pressure gauge using a special adapter. If you cannot find the proper adapter, you can fabricate one from a bolt and nut. Start the engine and check the pressure on the gauge, then detach the vacuum hose from the fuel pressure regulator to measure the fuel pressure. If the fuel pressure is not within specifications, check for vacuum at the hose, inspect the fuel filter, and look for any pinched or clogged hoses. If there are no issues with these components, check the fuel pump by removing the rear seat and the protective covering to access the fuel pump. Verify the pump runs by having an assistant turn the ignition switch to ON; you should hear a brief whirring noise. If the pump does not come on, disconnect the main fuel pump relay connector and install a jumper wire between the appropriate terminals, then check for battery voltage at the fuel pump electrical connector. If voltage is available but the pump doesn't run, replace the fuel pump. To test the main relay, remove it from its location, check for battery voltage at the connector, and verify continuity between the relay terminals using jumper wires. If there is no continuity, replace the relay, and check the wiring harness from the fuses to the relay and the pump.