Fuel Supply System

Fuel Supply System

Fuel Pump Control
When the ignition is turned on, the ECM grounds the PGM-FI main relay which feeds current to the fuel pump for two seconds to pressurize the fuel system. With the engine running, the ECM grounds the PGM-FI main relay and feeds current to the fuel pump. When the engine is not running and the ignition is on, the ECM 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 1,050 rpm.
Fuel cut-off action also occurs when engine speed exceeds 9,000 rpm, regardless of the position of the throttle valve, to protect the engine from over-revving.