TOHATSU BFT115A Service Manual page 94

TROUBLESHOOTING
ENGINE STARTS BUT STALLS SOON
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.
Start the engine.
Does engine stall?
YES
NO
3. Spark Plug Inspection
Remove and inspect spark plugs.
Is the spark plug wet?
YES
NO
4. Spark Test
Perform the spark test with each ignition coil (page 8-4).
Is there normal spark?
YES
NO
5. Intake air leak inspection
Check for secondary air leak between the silencer case and cylinder head.
Is there an air leak?
YES
NO
6. Fuel Flow Inspection
Inspect the fuel flow (page 5-130).
Is the fuel flow within specification?
YES
NO
4-4
– Perform alert system/warning system troubleshooting (page 4-17).
– GO TO STEP 2.
– GO TO STEP 3.
– Improper idle adjusting screw adjustment. Adjust the idle speed (page 3-13).
– • Incorrect spark plug heat range
• Incorrect spark plug gap
• Restriction or blockage between the silencer case and cylinder head
• Improper vapor separator float height
– GO TO STEP 4.
– GO TO STEP 5.
– Perform ignition system troubleshooting (page 8-3).
– • Loose IAC valve and/or throttle body mounting bolt
• Leaking or damaged throttle body and/or IAC valve gasket
• Loose IAT sensor
• Leaking or damaged IAT sensor O-ring
• Loose intake manifold and/or injector base mounting bolt
• Leaking or damaged intake manifold gasket
• Leaking or damaged injector base gasket
• Leaking or damaged fuel injector seal ring
– GO TO STEP 6.
– GO TO STEP 7.
– • Clogged, bent or damaged fuel tube
• Clogged fuel strainer (Low pressure side) (page 3-24)
• Clogged water separator (page 3-24)
• Faulty fuel pump (Low pressure side)
• Clogged vapor separator air vent tube or filter
• Faulty vapor separator (page 5-133)
• Clogged, bent or damaged fuel feed hose
• Clogged fuel strainer (High pressure side) (page 3-26)
• Faulty fuel pump (high pressure side)