TOHATSU BFT115A Service Manual page 93

6. Spark Test
Perform the spark test with each ignition coil (page 8-4).
Is there normal spark?
YES – GO TO STEP 7.
NO – Perform ignition system troubleshooting (page 8-3).
7. Cylinder Compression
Check the cylinder compression (page 14-44).
Is the compression normal?
YES – GO TO STEP 8.
NO – • Incorrect valve clearance
• Valve stuck open
• Cylinder/piston ring wear
• Blown cylinder head gasket
• Burned valve
• Incorrect cam chain tensioner adjustment
8. Vapor separator inspection
Loosen the vapor separator drain screw and check whether fuel flows out.
Does the fuel flow properly?
YES – GO TO STEP 9.
NO – • Clogged, bent or damaged fuel tube
• Closed fuel tank vent knob
• Primer valve leak
• Faulty primer valve
• Clogged fuel strainer (Low pressure side)
• Clogged water separator
• Faulty fuel pump (Low pressure side)
• Clogged vapor separator air vent tube or filter
• Faulty vapor separator
9. Fuel Pump (High pressure side) Inspection
You should hear the pump hum when the combination switch is turned "ON".
Is the hum heard?
YES – GO TO STEP 10.
NO – Perform fuel pump (high pressure side) system inspection (page 5-130).
10. Fuel Flow Inspection
Inspect the fuel flow (page 5-130).
Is the fuel flow within specification?
YES – GO TO STEP 11.
NO – • Clogged, bent or damaged fuel hose
• Clogged fuel strainer (High pressure side)
• Faulty fuel pump
11. Fuel injector inspection
Inspect the fuel injector (page 5-134).
Is the fuel injector normal?
YES – GO TO STEP 12.
NO – • Repair the open or short circuit in the fuel injector wire
• Faulty fuel injector
12. IAC valve inspection
Inspect the IAC valve (page 5-138).
Is the IAC valve normal?
YES – Replace the ECM with a new one and recheck.
NO – Replace the IAC valve with a new one and recheck.
TROUBLESHOOTING
4-3