There is one fuel injector for each cylinder. They spray fuel into the intake port, in front of the intake valve. When the injector is energized, the coil pulls the plunger up, opening the needle valve and allowing the fuel to pass through the injector. Opening of the injectors is controlled by the EFI computer. The injectors operate at low pressure and are open for only a fraction of a second at a time.
REMOVAL & INSTALLATION
See Figures 1, 2, 3, 4, 5, 6 and 7
- Disconnect the negative battery cable.
- Place a suitable container under the intake manifold to catch any dripping fuel.
- Remove the air intake chamber as detailed in "Cylinder Head Removal & Installation'' in Engine & Engine Overhaul of this repair guide. Throttle body also must be removed on 22R-E.
- On all engines, tag and disconnect all hoses and wires which interfere with injector removal.
- Unplug the wiring connectors from the tops of the fuel injectors and remove the two plastic clamps that hold the wiring harness to the fuel delivery pipe.
- Unscrew the four mounting bolts and remove the delivery pipe with the injectors attached. Do not remove the injector cover.
- Pull the injectors out of the delivery pipe.
- Insert new insulators into the injector holes on the intake manifold.
- Install the grommet and a new O-ring to the delivery pipe end of each injector.
- Apply a thin coat of gasoline to the O-ring on each injector and then press them into the delivery pipe.
- Install the injectors together with the delivery pipe in the intake manifold. Tighten the mounting bolts to 11-15 ft. lbs.
- Clip the wiring harness into the delivery pipe and then connect the wiring connectors to the top of each injector.
- Reconnect all hoses and wires.
- Install the throttle body and air intake chamber.
- Connect the battery cable.
- Start the engine and check for any fuel leaks.
See Figure 8
We recommend that any checking or testing of the injectors, other than that included below, be left to an authorized service facility.
Injector operation can be checked with the injectors installed in the engine. A sound scope is needed here (a stethoscope-like device you can usually rent from tool rental shops; they are also available new from most auto tool and parts jobbers).
With the engine running or cranking, check each injector for normal operating noise (a buzzing or humming), which changes in proportion to engine rpm. If a sound scope is not available to you, check injector operation by touching each injector with your finger. It should be buzzing. If no sound or an unusual sound is heard, check the wiring connector, or have the injector checked professionally.
Measure injector resistance by unplugging the wiring connector from the injector, and connecting an ohmmeter. Check the continuity at both terminals; resistance should be: