Yamaha SX150C Service Manual page 327

TRBL
ANLS
Items
3. Erratic engine
speed
TROUBLE SHOOTING FOR ELECTRIC FUEL
INJECTION
1. The engine is started, but will not run smoothly. The engine speed
drops during acceleration.
1. Inspect the high-pressure fuel lines.
1) Inspect for fuel
line leaks
2) Inspect the fuel
pressure
3) Inspect the
operation of the
fuel injector
4) Inspect the
diagnosis cord
5) Inspect the oxy-
gen density sensor
2. Inspect the ignition system.
1) Inspect the wire harness
2) Inspect the ignition spark
3) Inspect the ignition coil
4) Inspect the CDI unit output
peak voltage
5) Inspect the charge coil output
peak voltage
6) Inspect the pulser coil output
peak voltage
3. Inspect the ignition timing.
1) Inspect the diagnosis
cords
Symptoms
Fuel pressure is
out of specification
9-8
1 Inspect the 30-A fuse
2 Inspect the high-pres-
sure fuel pump opera-
tion
3 Inspect the main relay
4 Inspect the main relay
drive's ECU output
5 Inspect the pressure
regulator
1 Inspect the pulser coil
diagnosis cord
2 Inspect the crank position
sensor diagnosis cord
3 Inspect the engine cool-
ing water temperature
sensor diagnosis cord
E