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Fuel Pump Testing

NOTE: Fuel pump volume and pressure specifications are not available from manufacturer.
CAUTION: DO NOT  allow fuel to contact engine or electrical parts. Ensure open flame is not in area while testing fuel system components.
  1. Remove fuel pump. Before performing the following checks, pour some fuel through fuel pump to ensure check valves seal.
  2. Without blocking outlet and return fittings, check amount of arm play and force required to operate fuel pump. The same amount of force should be used during the following inspection. See Fig 1.
  3. Inspect inlet check valve. Block outlet and return fittings. Check for an increase in arm play and freedom of movement. Inspect outlet check valve. Block inlet fitting. Ensure arm locks.
  4. Check pump diaphragm. Block off inlet and outlet fittings. Ensure pump arm locks. Check oil seal. Block vent hole and ensure fuel pump arm locks. If fuel pump does not operate as described, replace pump.
Fig 1: Cross-Sectional View Of Fuel Pump
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