FDS14 - Check Pump Noise

Conditions that can produce fuel pump noise are:

- Low methanol fuel blends (less than 30%)

- High fuel volatility

- Low fuel levels (1/4 tank or less)

- and fuel temperature greater than 21°C (75°F).

Fuel system noise may become objectionable at start up or at high engine speeds. Noise heard under these conditions is considered normal and may be reduced if certain corrective actions are taken. In order to ensure that the fuel system noise complaints are addressed, diagnose any performance concerns first. Verify the noise concern and then follow the diagnostic procedure provided:

^ Key Off.

^ Observe Service Precautions to avoid fuel spillage and injury.

^ Drain fuel tank to less than a quarter tank, then fill tank to at least half with M85 fuel (15% gasoline, 85% methanol).

^ Start engine and check for excessive fuel pump noise.

^ Was pump noise reduced by adding M85 fuel?

YES -- Advise customer accordingly.

NO -- Go to FDS16. FDS15 - Check Pump Speeds