TOHATSU BFT115A Service Manual page 97

ENGINE DOES NOT RUN SMOOTHLY
ENGINE IDLE SPEED IS HIGHER 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 – Perform alert system/warning system troubleshooting (page 4-17).
NO – GO TO STEP 2.
2. Engine idle speed inspection
Adjust by turning the idle adjusting screw in or out (page 3-13).
Does the engine speed become normal?
YES – Improper original idle adjusting screw adjustment
NO – GO TO STEP 3.
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 – GO TO STEP 4.
NO – Faulty pressure regulator
4. IAC valve inspection
Replace the IAC valve with a new one and start the engine.
Is the engine idle speed normal?
YES – Faulty original IAC valve
NO – Replace the ECM with a new one and recheck.
TROLLING SPEED IS HIGHER 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 – Perform alert system/warning system troubleshooting (page 4-17).
NO – GO TO STEP 2.
2. Engine idle speed inspection
Adjust by turning the idle adjusting screw in or out (page 3-13).
Does the trolling speed become normal?
YES – Improper original idle adjusting screw adjustment
NO – GO TO STEP 3.
3. Neutral switch inspection
Inspect the neutral switch (page 10-19).
Is the neutral switch normal?
YES – GO TO STEP 4.
NO – Replace the neutral switch with a new one and recheck.
TROUBLESHOOTING
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