133
SYSTEM ANALYSIS
FUEL INJECTOR OPERATION
5
Dynamic Tests
Use the engine Monitor screen of the diagnostic
software program to monitor outboard system
voltage. Perform these tests while monitoring volt-
age. If voltage drops as RPM increases, check
stator and system voltage operation.
Run or crank outboard. Monitor the injector control
wire for each injector with an inductive timing light.
Make certain the inductive pickup is attached to
only one wire. Flashes on the timing light indicate
current in the circuit is being switched by the
EMM. The Dynamic Tests screen allows fuel injec-
tors or ignition to be turned off to a particular cylin-
der.
IMPORTANT: Some timing lights may not flash
consistently at cranking speeds. Always check the
orientation of the timing light pickup and the oper-
ation of the timing light to avoid needless part(s)
replacement.
Results:
Steady light activation on all injector wires and
consistent voltage readings:
• EMM injector control function is good.
Irregular or no light activation on some injector
wires:
• Test the resistance of each injector circuit. Mea-
sure resistance between the injector connector
and injector control wire at the EMM connector.
• Check battery cable connections.
• Make sure all grounds are clean and tight.
• Eliminate all other possibilities to isolate a faulty
EMM.
No light activation on any injector wires (outboard
cranks and starter turns flywheel):
• Confirm stator input to EMM, CPS operation,
and all grounds and wiring connections. Possi-
ble open circuit(s), faulty CPS or EMM.
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