Fuel Injector: Testing and Inspection
CHECKING INJECTOR OPERATING SOUNDChecking For Sound Of Operating Injectors:
AUDIO PERFORMANCE TEST:
Using a stethoscope, check the operational sound (click) made by the injectors (one at a time) during idle or cranking. Check that the sound is produced at shorter intervals as the engine speed increases.
NOTE: Other injectors may produce sound as they operate even if the injector under checking does not operate. Ensure that the sound from an adjacent injector is not being transmitted along the delivery pipe to an inoperative injector.
NO START TEST:
Verify voltage is reaching the fuel injector:
^ Disconnect the fuel injector electrical connector.
^ Connect a NOID tester to the electrical connector for the injector.
^ While the engine is being cranked, verify that the NOID tester light flickers.
CHECKING INJECTOR RESISTANCE
Checking The Resistance Of Injectors:
^ Disconnect the fuel injector electrical connector.
^ Measure the resistance between the injector terminals.
Standard Value: 13-16 Ohms (at 68°F)
NOTE: If the injectors test results are not within specifications or if the results deviate from above, replace the fuel injector.