Outboard motor troubleshooting
4-10
Symptom 1: Unstable engine idle speed, poor acceleration, poor performance, or limited engine
speed.
Symptom 2 Cause Checking steps
See
p
age
Throttle valve does
not mo
ve properly
Throttle valve malfunction
Check the throttle valve for proper
mo
vement.
6-21
Throttle link rod and the
thrott
le cable are not
installed properly
Adjust the throttle link rod and the
throttle cab
le.
6-22
3-6
Spark plug does not
produce a spar
k
(some cylinders)
Spark plug malfunction Check the spark plugs. 7-18
Short, open, or loose con-
nection in ignition coil cir-
cuit
Check for wiring continuity between
the ig
nition coil and the engine
ECM.
A-8
A-10
Check for wiring continuity between
the ig
nition coil and the fuse box.
A-8
A-10
Ignition coil malfunction Measure the ignition coil resistance. 5-28
Spark plug cap malfunction
Measure the spark plug cap resis-
tance.
5-29
Engine ECM malfunction Replace the engine ECM. 7-22
Fuel pressure is low
Fuel leakage Check for fuel leakage. 2-26
Clogged fuel filter element
Check the fuel filter element for dirt
and ob
structions.
6-6
Clogged fuel strainer
Check the fuel strainer for dirt and
obstr
uctions.
6-9
High-pressure fuel line mal-
function
Check the high-pressure fuel pump. 5-23
Pressure regulator mal-
function
Replace the pressure regulator. 6-15
Fuel not supplied
(some cylinders)
Fuel injector malfunction
Check the fuel injector operation
using the
YDIS.
5-23
Measure the fuel injector resistance. 5-23
Short, open, or loose con-
nection in fuel injector cir-
cuit
Measure the fuel injector input volt-
age.
5-23
Check for continuity between the
fuel inje
ctor and the fuse box.
A-8
A-10
Check for continuity between the
fuel inje
ctor and the engine ECM.
A-8
A-10
Clogged fuel injector filter Replace the fuel injector. 6-17
Engine ECM malfunction Replace the engine ECM. 7-22
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