Fuel Pressure: Notes

WARNING: ALWAYS relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components.

Basic diagnosis of fuel system should begin with determining fuel system pressure. If fuel pump fails to run on fuel-injected models, inspect power supply to main relay. If all power supplies are present (i.e. battery, ignition and starter switch during cranking), perform functional test of main relay. See WIRING DIAGRAMS and SYSTEM/COMPONENT TESTS - EFI articles.