TOHATSU BFT115A Service Manual page 98

TROUBLESHOOTING
4. Pressure regulator inspection
Check the fuel pressure and record it (page 5-129).
Disconnect the pressure regulator control tube.
Check the fuel pressure.
Is the fuel pressure higher with the control tube disconnected?
YES
NO
5. IAC valve inspection
Replace the IAC valve with a new one and start the engine.
Warm up the engine and check the trolling speed.
Is the engine trolling speed normal?
YES
NO
TROLLING SPEED IS LOWER THAN SPECIFIED AFTER WARMING UP
1. Alert system inspection
Turn the combination switch ON.
Check the warning buzzer sound.
Does the warning buzzer sound twice and then keep sounding?
YES
NO
2. Engine idle speed inspection
Adjust by turning the idle adjusting screw in or out (page 3-13).
Does the engine speed and/trolling speed become normal?
YES
NO
3. Pressure regulator inspection
Check the fuel pressure and record it (page 5-129).
Disconnect the pressure regulator control tube.
Check the fuel pressure.
Is the fuel pressure higher with the control tube disconnected?
YES
NO
4. IAC valve inspection
Replace the IAC valve with a new one and start the engine.
Warm up the engine and check the trolling speed.
Is the engine trolling speed normal?
YES
NO
4-8
– GO TO STEP 5.
– Faulty pressure regulator
– Faulty original IAC valve
– Replace the ECM with a new one and recheck.
– Perform alert system/warning system troubleshooting (page 4-17).
– GO TO STEP 2.
– Improper original idle adjusting screw adjustment
– GO TO STEP 3.
– GO TO STEP 4.
– Faulty pressure regulator
– Faulty original IAC valve
– Replace the ECM with a new one and recheck.