Fuel Pump: Description and Operation

Fuel Pump Control
- When the ignition switch is initially turned on, the ECM/PCM supplies ground to the PGM-FI main relay that supplies current to the fuel pump for two seconds to pressurize the fuel system.
- When the engine is running, the ECM/PCM supplies ground to the PGM-FI main relay that supplies current to the fuel pump.
- When the engine is not running and the ignition is on, the ECM/PCM cuts ground to the PGM-FI main relay which cuts current to the fuel pump.

Fuel Cut-off Control
- During deceleration with the throttle valve closed, current to the fuel injectors is cut off to improve fuel economy at speeds over the following rpm:
- D16Y5 engine (M/T): 850 rpm
- D16Y5 engine (CVT), D16Y8 engine (USA M/T): 920 rpm
- D16Y8 engine (USA A/T), D16Y7 engine (USA A/T): 910 rpm
- D16Y8 engine (Canada M/T), D16Y7 engine (Canada): 990 rpm
- D16Y8 engine (Canada M/T): 1,000 rpm
- B16A2 engine: 970 rpm

- Fuel cut-off action also takes place when engine speed exceeds 6,900 rpm (D16Y5, D16Y7 engine; D16Y8 engine:7,000 rpm, B16A2 engine: 8,100 rpm), regardless of the position of the throttle valve, to protect the engine from over-revving. With '99 D16Y7 engine (A/T) and '99 D16Y8 engine (A/T), the PCM cuts the fuel at engine speeds over 5,000 rpm when the vehicle is not moving.