FUEL INJECTION / IGNITION / EXHAUST SYSTEMS
5.37
2004 Four Stroke PWC Service Manual
Troubleshooting -- Engine Turns--Over; Will Not Start
System / Component
Inspection Procedure
Suspected Problem
Battery
Condition of Battery
Static battery voltage must be at least 12
Vdc.
Voltage drop cannot drop below 10.5 Vdc
while pushing START button.
Clean battery of any foreign material or cor-
rosion in or around battery terminals.
Verify battery connections are clean and
tight.
Ignition System
Insert lanyard into STOP switch. An audible
series of relay switching and clicking should
be heard.
Move the throttle flipper from closed to open
several times. The throttle plate must move
in conjunction with each throttle flipper
movement.
Verify that no 15AMP fuses are blown in the
engine fuse block.
Inserting the lanyard into the STOP switch
provides battery voltage to the START but-
ton and to the ECU.
If the starter motor turns when the START
button is pushed, then the START/STOP
switch is OK should be providing battery
voltage to the ECU via the PURPLE circuit.
Main Relay
Provide battery voltage to PIN 3 and ground
PIN 10. Continuity should be seen between
PINS 11 and 2.
Provide battery voltage to PIN 3 and ground
PINS 10 and 7. Continuity should be seen
between PINS 15 / 8 and 13, 6, 5, 4, and 7.
Defective relay. During normal operation,
the ECU grounds PINS 7 and 10 to close
the main ECU power relay and fuel pump
driver relay.
The fuel pump driver relay also supplies
battery voltage to the lambda sensor, igni-
tion coils, fuel injectors and wastegate sole-
noid.
ECU (Engine Management System)
Use the Digital Wrench
t
diagnostic soft-
ware to review current data values and
download any trouble codes.
Repair any problems that are triggering
trouble codes.
Failed ECU or EMS components preventing
engine from starting.
Fuel System
Verify fresh fuel is in the fuel tank.
Verify fuel rail pressure is meeting specifica-
tion.
Test each fuel injector for correct resistance.
Check 10AMP fuel pump fuse located in the
chassis harness fuse block.
Check condition of fuel filter. If foreign ma-
terial is found in tank, clean tank and re-
place fuel filter.
Low or no fuel in tank.
Damaged fuel injectors.
Damaged fuel delivery system of fuel pump.
Propulsion System
Verify there are no damaged parts in the
inlet pump or impeller housing.
Mechanical failure causing high friction load
on starting system.
Starting System
Verify condition of starter motor.
Check voltage drop when START button is
pressed.
Voltage drop cannot exceed 10.5 vDC while
pushing START button.
Mechanical Condition of Engine
Check spark plug for correct plug and prop-
er gap.
Check cylinder compression and compare
against specification.
Incorrect spark plug usage can cause seri-
ous engine damage.
Cylinders with low compression will cause
hard staring issues and poor performance.
Summary of Contents for msx 110
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