Evinrude E-tec 75 HP, Service Manual

Page: 121 / 344

121
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 charging system 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:
•
Check the voltage on each circuit. Test the
resistance of each injector circuit. Measure
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 (55 V circuit) to
EMM
, CPS
operation, and all grounds and wiring connec-
tions. Possible open circuit(s), faulty CPS or
EMM
.
IMPORTANT:
This test is operating injector on
12 V battery power. Injector activation should be
carefully confirmed.