Fuel Supply System

Fuel Pump Control

When the ignition is turned on, the ECM/PCM grounds the PGM-FI main relay which feeds current to the fuel pump for 2 seconds to pressurize the fuel system. With the engine running, the ECM/PCM 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/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 1,100 rpm.

Fuel cut-off action also occurs when engine speed exceeds 6,500 rpm, regardless of the position of the throttle valve, to protect the engine from over-revving. On A/T models, when the vehicle is stopped, the PCM cuts the fuel at engine speeds over 5,000 rpm.