Fuel Injector: Service and Repair

FUEL INJECTOR

On-Vehicle Inspection
1) Using sound scope or such, check operating sound of injector when engine is running or cranking.
Cycle of operating sound should vary according to engine speed.
If no sound or an unusual sound is heard, check injector circuit (wire or coupler) or injector.
2) Disconnect coupler from injector, connect ohmmeter between terminals of injector and check resistance.

Resistance of injector: 12.0 - 13.0 ohms at 20°C, 68°F

If resistance is out of specification, replace.
3) Connect coupler to injector securely.

Removal
1) Relieve fuel pressure according to procedure.
Fuel Pressure Release

2) Disconnect battery negative cable at battery.
3) Disconnect fuel injector couplers.
4) Disconnect vacuum hose from fuel pressure regulator.
5) Remove fuel delivery pipe bolts.
6) Remove fuel injector(s).

Inspection

WARNING: As fuel is injected in this inspection, perform in a well ventilated area and away from open flames.
Use special care to prevent sparking when connecting and disconnecting test lead to and from battery.

1) Install injector and fuel pressure regulator to special tool (injector checking tool).

Special Tool
(A): 09912-58421

2) Connect special tools (hoses and attachment) to pipes of vehicle.

Special Tool
(B): 09912-58431
(C): Hose attachment-2 (including tool set)

3) Connect special tool (test lead) to injector.

Special Tool
(D): 09930-88530

4) Install suitable vinyl tube onto injector nozzle to prevent fuel from splashing out when injecting.
5) Put graduated cylinder under injector as shown.
6) Operate fuel pump and apply fuel pressure to injector as follows:

When using SUZUKI scan tool:
(1) Connect SUZUKI scan tool to DLC with ignition switch OFF.
(2) Turn ignition switch ON, clear DTC and select "MISC TEST" mode on SUZUKI scan tool.
(3) Turn fuel pump ON by using SUZUKI scan tool.

When not using SUZUKI scan tool:
(1) Remove fuel pump relay from connector.
(2) Connect two terminals of relay connector using service wire as shown in figure.

CAUTION: Check to make sure that connection is made between correct terminals. Wrong connection can cause damage to ECM, wire harness, etc.

(3) Turn ignition switch ON.

7) Apply battery voltage to injector for 15 seconds and measure injected fuel volume with graduated cylinder.
Test each injector two or three times. If not within specification, replace injector.

Injected fuel volume: 44 - 54 cc/15 sec. (1.49/1.55-1.82/1.90 US/Imp. oz/15 sec.)

8) Check fuel leakage from injector nozzle. Do not operate injector for this check (but fuel pump should be at work).
If fuel leaks more than following specifications, replace.

Fuel leakage: Less than 1 drop/min.

Installation
For installation, reverse removal procedure and note following precautions.
- Replace injector O-ring with new one using care not to damage it.
- Check if cushion is scored or damaged. If it is, replace with new one.
- Apply thin coat of fuel to O-rings and then install injectors into delivery pipe and intake manifold.
Make sure that injectors rotate smoothly. If not, probable cause is incorrect installation of O-ring. Replace O-ring with new one.
- Tighten delivery pipe bolts and make sure that injectors rotate smoothly.
- After installation, with engine "OFF" and ignition switch "ON," check for fuel leaks around fuel line connection.