Fuel Injector: Testing and Inspection

1987 PRELUDE & 1987---88 ACCORD
Ensure idle speed, ignition timing and idle CO percentage are within specification before performing test.
W/Engine Running
1. With engine idling, disconnect each injector connector individually and note change in idle speed.
2. If idle speed drop is approximately equal for each cylinder, injectors are normal.
3. If idle speed or quality remains the same when a particular injector is disconnected, replace that injector and repeat test.
4. Using stethoscope, check clicking sound of each injector with engine idling.
5. If any injector fails to make typical clicking sound, replace injector and again check for clicking sound.
6. If clicking sound still cannot be heard, proceed as follows:
a. Check for short circuit, wire breakage or poor connection in yellow/black wire between main relay and resistor.
b. Check whether resistor is open or corroded. Refer to ``Fuel System Resistor.''
c. Check for short circuit, wire breakage or poor connection in red/black wire between resistor and injector.
d. Check for short circuit, wire breakage or poor connection in wire between injector and ECU.
e. If results in steps a through d are satisfactory, test ECU.
Engine Cannot Be Started
1. Remove injector electrical connector and measure resistance between injector terminals.
2. If resistance is not 1.5---2.5 ohms, replace injector.
3. If resistance is as specified, check fuel pressure.
4. If fuel pressure is within specification, proceed as follows:
a. Check for short circuit, wire breakage or poor connection in yellow/black wire between main relay and resistor.
b. Check whether resistor is open or corroded. Refer to ``Fuel System Resistor.''
c. Check for short circuit, wire breakage or poor connection in red/black wire between resistor and injector.
d. Check for short circuit, wire breakage or poor connection in wire between injector and ECU.
e. If results in steps a through d are satisfactory, test ECU.