TOHATSU BFT 250A, Service Manual

Page: 103 / 639

4-11
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TROUBLESHOOTING
8. Fuel injector inspection
Inspect the fuel injector (page 5-116).
Is the fuel injector normal?
YES – GO TO STEP 9.
NO – • Repair the open or short circuit fuel injector wire
• Faulty fuel injector
9. IAC valve inspection
Replace the IAC valve with a new one and start the engine.
Is the engine speed stable during idle and trolling?
YES – Faulty original IAC valve.
NO – Replace the ECM with a new one and recheck.
ENGINE SPEED DOES NOT INCREASE
1. Throttle cable inspection
Inspect the throttle cable (page 3-11).
Is the throttle cable adjustment correct?
YES – GO TO STEP 2.
NO – Improper throttle cable adjustment (page 3-11).
2. Propeller inspection
Match the propeller.
Is the propeller correct?
YES – GO TO STEP 3.
NO – Propeller mismatched.
3. Fuel Flow Inspection
Inspect the fuel flow (page 5-113).
Is the fuel flow within specification?
YES – GO TO STEP 4.
NO – • Clogged fuel strainer (Low pressure side) (page 3-27)
• Clogged water separator (page 5-93)
• Clogged or damaged fuel tube
• Faulty fuel pump (Low pressure side)
• Clogged vapor separator air vent tube or filter
• Clogged fuel feed hose
• Clogged fuel strainer (High pressure side) (page 5-106)
• Faulty vapor separator (page 5-115)
• Faulty fuel pump (high pressure side)
4. Pressure regulator inspection
Inspect the fuel pressure and record it (page 5-111).
Disconnect the pressure regulator vacuum tube.
Inspect the fuel pressure.
Is the fuel pressure higher with the vacuum tube disconnected?
YES – GO TO STEP 5.
NO – Faulty pressure regulator.
5. Valve clearance inspection
Inspect the valve clearance (page 3-15).
Is the valve clearance correct?
YES – GO TO STEP 6.
NO – Improper valve clearance adjustment (page 3-15).