Yamaha F225F Service Manual page 156

TRBL
SHTG
Symptom 2
Fuel not supplied (all
cylinders)
Compression pressure
is low
4-31
Troubleshooting
Cause
—
Pinched or kinked fuel hose
Fuel leakage
Clogged fuel filter element
High-pressure fuel pump mal-
function
Short, open, or loose connec-
tion in high-pressure fuel pump
circuit
Blown fuse
High-pressure fuel pump relay
malfunction
Short, open, or loose connec-
tion in low-pressure fuel pump
circuit
Blown fuse
Low-pressure fuel pump mal-
function
—
Improper valve timing
Compression leakage
Checking step
Measure the fuel pressure.
Check the fuel hose.
Check the fuel line for leakage.
Check the fuel filter element for dirt and
obstructions.
Check the high-pressure fuel pump oper-
ation using the YDIS.
Measure the high-pressure fuel pump
resistance.
Check the high-pressure fuel pump input
voltage.
Check for wiring continuity between the
high-pressure fuel pump and engine
ECM.
Check for wiring continuity between the
high-pressure fuel pump and high-pres-
sure fuel pump relay.
Check the fuse.
Check the high-pressure fuel pump relay.
Check the low-pressure fuel pump input
voltage.
Check for wiring continuity between the
low-pressure fuel pump and engine
ECM.
Check for wiring continuity between the
low-pressure fuel pump and main relay.
Check the fuse.
Check the low-pressure fuel pump resis-
tance.
Measure the compression pressure.
Check the valve timing.
Check the timing belt.
Check the valve for bends and sticking.
Check the piston and piston rings for
damage.
Check the cylinder for scratches.
See
page
6-6
6-1
6-1
6-12
5-37
5-37
5-37
5-37
A-5
5-37
A-5
5-3
5-38
5-37
5-37
A-5
5-37
5-3
A-3
5-37
7-1
7-39
7-39
7-53
7-78
7-78