Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Fuel Delivery
An electric fuel pump (located inside fuel tank) supplies fuel under pressure to throttle body. The ECM actuates the fuel pump through the fuel pump relay when the ignition is in the "ON" or "START" position. The fuel pump relay is located in relay panel. If engine stalls or is not cranked within one second after ignition is turned on, ECM will deactivate fuel pump.
The fuel pressure regulator is an integral part of the throttle body, and provides pressurized fuel at up to 20 psi. A diaphragm-operated relief valve regulates fuel pressure. Relief valve is exposed to atmospheric pressure on bottom side and top side, and senses fuel pressure to maintain constant pressure between 9 and 12 psi across fuel injectors. Unused fuel is returned to fuel tank through fuel return line.
During normal engine operation, 2 fuel injectors are actuated alternately by ECM. The injectors direct metered atomized fuel into throttle bores above throttle valves. Both injectors are actuated simultaneously during cranking. See Fig 1 .
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.