Shadow L4-135 2.2L SOHC VIN D FI (1992)
Fuel Injector: Testing and Inspection
Fuel Injector Balance Test
Note:
Make sure injectors have been cleaned with an approved cleaner prior to testing.
Purpose
The injector balance test verifies a balanced distribution of fuel to all cylinders.
Procedure
1.
Connect a fuel pressure gauge at the schrader valve or in-line before the fuel pressure regulator (refer to gauge manufacturer instructions).
2.
Pressurize the fuel rail by turning ignition to ON position, and energizing the fuel pump by selecting ASD in the ATM test mode with the DRB II
or equivalent scan tool. Fuel pressure should rise to maximum working pressure.
3.
Remove injector harness connector and connect an injector pulse tester.
4.
Pulse one injector at a time. Allow pressure to rise and stabilize in between each injector tested.
Note:
The time each injector is pulsed is very important. Each injector should be pulsed at the same time interval, (example: ms each).
5.
The rate of drop should be even across all the injectors. All pressure drops should be within 3% of each other, if not replace injector.
6.
If there is no pressure drop when an injector is pulsed, verify the connection between the injector and pulse tester. If this connection is good, a
check of the injector circuit is required.
Injector Circuit Check
1.
Test the resistance of the injector.
^ If resistance is OK verify power to injector by connecting the injector harness and starting engine and proceed to step 2.
^ If resistance is not OK replace the injector.
2.
Use a "NOID" light to check for pulses (light off and on).
^ If light pulses, recheck pressure drop to verify malfunction.
^ If it does not pulse check the injector control circuit. See Computers and Control Systems/ Testing and Inspection/ Diagnostic Charts/
No Fault Tests.
Note:
It may not be possible to connect a noid light to the harness while connected to injector. If this is the case disconnect harness and connect noid
light to harness and check pulses.
