Vapor Separator Checks
Fuel Supply
The vapor separator must provide “solid” fuel to the fuel circulation pump. Make sure the vapor separator receives the proper fuel supply from the fuel lift pump.
Perform Lift Pump Pressure Test on p. 187.
- Use primer to check fuel movement through fuel lift pump.
- Outboard runs: Check pressure with outboard running.
- Outboard does not run: Check pressure with outboard cranking.
Venting
Monitor the vapor separator vent hose. No fuel or a trace of fuel is acceptable. Excessive fuel discharge indicates a vapor separator vent malfunction. Monitor vent for presence of fuel during testing. Temporarily install clear tubing for monitoring. Replace vapor separator if the venting of fuel is continuous.
Fuel Delivery to Lift Pump
Perform the Lift Pump Vacuum Test on p. 187. Make sure no restrictions or air leaks exist in the fuel supply hose or boat fuel system.
FUEL INJECTOR OPERATION
Static Tests
Perform the Fuel Injector Static Test using the diagnostic program. Static tests are performed with the outboard “static” or not running. Listen for an audible “click” from each injector when it is actuated.
IMPORTANT: This test is operating injector on 12 V battery power / system voltage (55 V). Battery must be fully charged and connections must be clean and tight. The start assist circuit (SAC) of the EMM should convert battery voltage (12 V) to 30 V of system voltage. Injector activation should be carefully confirmed.
Results:
No injectors actuate:
- Use the diagnostic software to monitor system voltage (55 V). Check individual injector circuits from EMM to injectors. See Stator Voltage Output Test on p. 142 if system voltage is low.
Some injectors actuate; some do not: - Make sure individual injector circuits and injectors are functional. See Fuel Injectors on p. 184.
All injectors actuate:
- Confirm fuel system pressure and fuel supply to injectors.
Dynamic Tests
Use the engine Monitor screen of the diagnostic software program to monitor outboard system voltage. Perform these tests while monitoring voltage. 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 injectors or ignition to be turned off to a particular cylinder.
IMPORTANT: Some timing lights may not flash consistently at cranking speeds. Always check the orientation of the timing light pickup and the operation 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. 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 to EMM, CPS operation, and all grounds and wiring connections. Possible open circuit(s), faulty CPS or EMM.
