FUEL COMPONENT TESTS
Contact with a rotating propeller is likely to result in serious injury or death. Assure the engine and prop area is clear of people and objects before starting engine or operating boat. Do not allow anyone near a propeller, even when the engine is off. Blades can be sharp and the propeller can continue to turn even after the engine is off. Remove propeller before servicing and when running the outboard on a flushing device. DO NOT run the engine indoors or without adequate ventilation or permit exhaust fumes to accumulate in confined areas. Engine exhaust contains carbon monoxide which, if inhaled, can cause serious brain damage or death.
Use caution when working on any pressurized fuel system. Wear safety glasses and work in a well ventilated area. Extinguish all smoking materials and make certain no open flames or ignition sources exist. Before starting any fuel system service, carefully relieve fuel system pressure. Failure to properly relieve fuel system pressure can result in spraying fuel and/or excessive fuel spillage during servicing. Fuel is flammable and can be explosive under certain conditions.
Fuel Injectors
Pressure Test
This test requires Injector Test Fitting kit, P/N 5005844.
Disconnect the battery cables at the battery.
Relieve fuel system pressure. See Relieving Fuel System Pressure on p. 184.
Perform test with injector mounted to cylinder head and fittings installed with manifold retainer.
Use cap and tie strap to seal off outlet fitting and connect a 0 to 30 psi (0 to 207 kPa) pressure tester to the inlet fitting. Pressurize the injector to 30 psi (207 kPa). Pressure must hold for at least five minutes.
- Outlet fitting
- Inlet fitting
Static Test
Use the Evinrude Diagnostics Software program to test circulation pump and fuel injectors.
Refer to FUEL DELIVERY on p. 131 for additional test procedures.
Static tests are performed when outboard is not running. Listen carefully for fuel pump and injector activation. These tests are operating components on battery voltage. The fuel pump uses 12 V circuit and the injectors use 55 V circuit.
Static Tests Screen
Resistance Test
Disconnect the battery cables at the battery.
Use a digital multimeter to measure the injector circuit and coil resistance.
| Fuel Injector Coil Resistance | 2 to 3 Ω @ 72°F (22°C) |
|---|
Use electrical test probe kit, P/N 342677, and a multimeter to check resistance. Wire harness adaptor leads, P/N 342228 can be used to make connection at EMM J1-B connector.
Measure resistance between pin 1 of injector connector and the appropriate pin location of EMM J1-B connector. Refer to engine wiring diagram for specific EMM J1-B connector pin location for the injector circuit being tested.
Fuel Supply
Fuel System Pressure Test
Relieve fuel system pressure. See Relieving Fuel System Pressure on p. 184.
After relieving fuel system pressure, install a 0 to 100 psi (0 to 690 kPa) Fuel Pressure Gauge, P/N 5000902 or equivalent, to the upper fuel pressure test fitting.
- Fuel pressure gauge
- Test fitting
START outboard and check pressure. System pressure should be 20 to 35 psi (138 to 241 kPa).
Shut OFF outboard. Monitor pressure gauge.
Pressure should not drop below 15 psi (103 kPa).
If outboard does not run, prime fuel system and crank outboard; check circulation pump operation; check fuel system pressure.
Results:
Normal pressure
- Observe pressure reading after outboard is shut OFF.
- Proceed to Lift Pump Pressure Test on p. 182. Pressure drops after outboard shut OFF
- Leaking fuel injector
- Leaking pressure regulator
- External fuel system leak
High pressure
- Suspect restricted filter or fuel return fitting of vapor separator, damaged pressure regulator in vapor separator, or restricted fuel return manifold.
Low pressure
- Check fuel supply to fuel lift pump. Refer to Lift Pump Vacuum Test on p. 182. Higher vacuum readings indicate restrictions in the fuel supply. Repair or replace as needed.
- Restricted fuel filter/water separator assembly.
- Lift pump not supplying adequate fuel to vapor separator. Refer to Lift Pump Pressure Test on p. 182.
- If the above requirements are met and vapor separator remains full of fuel, suspect damaged circulation pump. Replace vapor separator assembly.
No pressure
- Check electrical circuit and ground connections for circulation pump.
- Voltage present and pump does not run. Repair connection or replace vapor separator assembly.
Pressure Regulator Test
Refer to Vapor Separator on p. 186 to remove vapor separator.
Make sure filter is not clogged. Clean or replace as needed.
Apply oil to valve and connect pressure pump and hose to the fuel return fitting of vapor separator.
Apply pressure to check regulator operation. The pressure should open check valve at approximately 15 psi (103 kPa).
- Filter
- Fuel return fitting
- Pressure regulator
Circulation Pump Resistance Test
Disconnect the battery cables at the battery.
Use a digital multimeter to measure the fuel pump circuit and coil resistance.
| Fuel Pump Resistance | 1 Ω @ 77°F (25°C) |
|---|
Lift Pump Pressure Test
Install a 0 to 15 psi (0 to 103 kPa) Fuel Pressure Gauge, P/N 5006397 or equivalent, to the lower fuel pressure test fitting.
- Fuel pressure gauge
- Test fitting
Prime the fuel system and check for leaks. START outboard and run at idle speed. Hold gauge level with inlet fitting and monitor gauge for pressure reading.
Pressure should stabilize and gauge must not indicate less than 4 psi (27 kPa).
Results:
Normal pressure
- Perform the Lift Pump Vacuum Test on p. 182. Make certain no air leaks or restrictions exist in the fuel supply hose or boat fuel system.
Low pressure
- Check pulse hoses and fittings for restrictions.
- Perform the Lift Pump Vacuum Test on p. 182. Make sure no air leaks or restrictions exist in the fuel supply hose or boat fuel system.
- Check fuel flow through fuel lift pump. Use fuel primer bulb to force fuel through pump. No pressure
- Check pulse hoses and fittings restrictions.
- Check fuel flow through fuel lift pump. Use fuel primer or primer bulb to force fuel through pump.
- Momentarily prime or squeeze primer bulb to check gauge operation.
- Check pulse hose and fittings for restrictions.
Lift Pump Vacuum Test
Confirm fuel supply to the fuel lift pump.
Temporarily install a vacuum gauge, T-fitting, and 8 in. (20.3 cm) of clear vinyl hose between the fuel supply hose and fuel lift pump (inlet). Secure connections with tie straps to prevent fuel or air leaks.
Do not use fuel primer bulb, manual fuel primer, or electric fuel pump primer to restart outboard. A positive pressure in the fuel supply could damage some vacuum gauges.
START outboard and run at FULL THROTTLE for at least two minutes. Monitor clear vinyl hose for the presence of air. Air bubbles indicate a faulty hose, connection, or fuel tank pick-up. Repair, if necessary, before proceeding.
There should be no air or vapor bubbles visible in the clear hose. The maximum inlet fuel vacuum should not exceed 4 in. Hg. (13.5 kPa) at the inlet to the fuel lift pump under any operating conditions (IDLE to WOT).
A higher vacuum indicates an excessive restriction in the fuel supply. Repair as needed. Refer to Fuel System Requirements on p. 41 for fuel supply component requirements.
Lift Pump Diaphragm Test
Perform this test only if a damaged pump is suspected. This test does not confirm the performance of internal fuel pump check valves.
Pump diaphragms can be pressure tested by removing both pulse hoses from the crankcase fittings.
Apply 15 psi (103 kPa) to each of the pulse hoses of the pump. Both sides of pump should hold pressure.
Replace lift pump if either side fails to hold pressure.
- Pulse fitting
Anti-Siphon Valve Test
Remove anti-siphon valve from fuel tank. Install adapter fittings and a 36 in. (91.4 cm) length of clear hose to the inlet side (tank end) of valve.
- Anti-siphon valve
- Adapter fitting
- Clear hose
Fill clear hose with water to a height of 20 in. (500 mm). Water must NOT flow through valve. An occasional drip is acceptable. Replace valve if water drips continuously.
Increase height of water to 25 in. (630 mm). Water should flow through valve as water level reaches 25 in. (630 mm). Replace the anti-siphon valve if test
results are different.
