Service manual

90-898303

4-6

Fuel Injectors (c)

The fuel injectors are located on the fuel rail. The injector valve body consists

of a solenoid actuated needle and seat assembly. The injector receives

signals from the EFI Electronic Control Module. These signals determine how

long the needle is lifted from the seat (pulse width) allowing a measured fuel

flow. The pulse width will widen (richer) or narrow (leaner) depending on

various signals received from sensors connected to the EFI ECM. The ECM

receives a signal from the crank position sensor to fire each injector

accordingly. In the “start” position, injector pulse widths are increased as

engine head temperature is reduced to provide adequate fuel for quick start

up.

A 12 wire harness connects the fuel injectors to the ECM. The RED wire is at

12 volts and connects to all injectors. The BLUE, YELLOW, WHITE, BROWN,

PURPLE and ORANGE wires each go to individual injectors and are normally

at 12 volts for a zero differential. To fire the injectors this voltage is brought

down to near ground creating a potential across the injectors.

Fuel Pressure Regulator (p)

The fuel pressure regulator is located on top of the vapor separator and is

continuously regulating fuel pressure produced by the electric fuel pump. The

electric pump is capable of producing 90 psi (621 kPa) of fuel pressure. The

pressure regulator limits fuel pressure at the injectors to 41 to 45 psi (283 to

310 kPa).

Notes

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