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Engine Controls - Basic Testing - 2.7L: Overview Toyota T100 I

Testing & Diagnostics 2 illustrations ~336 words

FUEL PUMP OPERATION

Note. Fuel pump operation may be checked by using scan tester or by applying battery voltage to electric fuel pump.

Checking Fuel Pump Operation Using Scan Tester

  1. Install scan tester on data link connector No. 3. (Scheme 1) Turn ignition on. DO NOT start engine.
  2. Using scan tester manufacturer's instructions, activate electric fuel pump. Listen for fuel pump operating sound and feel for pressure in fuel line near fuel filter. Turn ignition off. Remove scan tester. If fuel pump operates, check fuel pressure. See «FUEL PRESSURE»(ref-21581-S38022123052001010300000).
  3. If fuel pump does not operate, EFI main relay, circuit opening relay or fuel pump relay (if used) may be defective. For relay application and explanation of relay operation, see «FUEL PUMP CONTROL CIRCUIT»(ref-21581-S23891151542001010300000).
  4. If relays are okay, check wiring circuit and fuses. If fuel pump does not operate, check for defective fuel pump or defective fuel pump ground. See wiring diagram in the WIRING DIAGRAMS article.

Fuel Pump Operation By Applying Battery Voltage To Electric Fuel Pump

  1. It may be necessary to lower fuel tank for access to electrical connector at fuel pump. Disconnect electrical connector for fuel pump. NOTE: Electrical connector for fuel pump is located near fuel pump.
  2. Connect battery voltage to specified terminals on fuel pump to activate fuel pump. (Scheme 2) Listen for fuel pump operating sound and feel for pressure in fuel line near fuel filter. If fuel pump operates, check fuel pressure. See «FUEL PRESSURE»(ref-21581-S38022123052001010300000). Disconnect battery voltage from fuel pump.
  3. If fuel pump fails to operate, replace fuel pump. If fuel pump will not operate while trying to start engine, EFI main relay, circuit opening relay or fuel pump relay (if used) may be defective. For explanation of relay operation, see «FUEL PUMP CONTROL CIRCUIT»(ref-21581-S23891151542001010300000).
  4. If relays are okay, check wiring circuit, fuses and fuel pump ground. See wiring diagram in the WIRING DIAGRAMS article. Rein-stall electrical connector and remaining components.

Scheme 1

Scheme 1
Scheme 1

Scheme 2

Scheme 2
Scheme 2

See also:
• ADJUSTMENTS - 2.7L

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