Fuel Injector Circuit

Fuel Injector Circuit:

The following procedure should be used to check for a "NO POWER TO INJECTOR" condition. Refer to the schematic diagram and test the circuit with the diagnostic chart.

Wire color code identification:

L: Blue
B: Black
Y: Yellow
G: Green
R: Red
W: White
Br: Brown
Lg: Light green
Gr: Gray

Fuel Injector Circuit Diagnostic Chart:

FUEL INJECTOR CONTROL SYSTEM DIAGNOSTIC CHART

CHECK FUEL INJECTOR OPERATION
Using a stethescope, confirm that all injectors "CLICK" while cranking the engine.

Fuel Injector Connector:

CHECK VOLTAGE AT INJECTORS
1. Disconnect connector F109 (injector sub-harness).
2. Turn the key "ON".
3. Using a voltmeter, check voltage between male connector terminal and ground.

Connector & terminal: Voltage:
(F109)1-Ground Above 9V

CHECK FUEL INJECTORS
1. Turn the key "OFF".
2. Using an ohmmeter, check the resistance between fuel injector terminals.

Connector & terminal: Resistance:
(F109)1-2 10 - 18 Ohm
(F109)1-3 10 - 18 Ohm
(F109)1-4 10 - 18 Ohm

If not within specification, proceed to CHECK ENGINE HARNESS 2 below.

ECU Connector:

CHECK VOLTAGE BETWEEN ECU AND FUEL INJECTORS
1. Connect connector F109.
2. Turn ignition key "ON".
3. Using a voltmeter, measure voltage between ECU connector terminal and body. (Back probe ECU connector.)

Connector & terminal: Voltage:
(F119)12-Ground Above 8V
(F119)25-Ground Above 8V
(F119)11-Ground Above 8V

4. Turn key "OFF".
5. Disconnect connector F119 from ECU.
6. Using and ohmmeter, check resistance between ECU harness connector terminal and ground.

Connector & terminal: Resistance:
(F119)13-Ground Below 10 Ohm
(F119)26-Ground Below 10 Ohm

Engine Harness 2:

CHECK ENGINE HARNESS 2

NOTE: Removal of the throttle chamber will improve access to the injector terminals.

1. Disconnect injector terminals.
2. Using an ohmmeter, check resistance between connector F109 and injector terminals F110, F111 and F112.

Connector & terminal: Resistance: Cyl:
(F109)2-(F110)2 Below 1 Ohm #1
(F109)3-(F111)2 Below 1 Ohm #2
(F109)4-(F112)2 Below 1 Ohm #3

(F109)1-(F110)1 Below 1 Ohm #1
(F109)1-(F111)1 Below 1 Ohm #2
(F109)1-(F112)1 Below 1 Ohm #3

(F110)1-2 Infinite Ohm #1
(F111)1-2 Infinite Ohm #2
(F112)1-2 Infinite Ohm #3

(F109)2-3 Infinite Ohm
(F109)2-4 Infinite Ohm
(F109)3-4 Infinite Ohm