Fuel Injection Control

DESCRIPTION AND OPERATION
The injector drive time and timing are controlled to supply the engine with the mixture at the most appropriate air-fuel ratio for the engine operating condition which changes constantly. One injector is provided for the intake port of every cylinder.

Fuel is delivered under pressure by the fuel pump from the fuel tank and its pressure is regulated by the fuel pressure regulator. The fuel having its pressure regulated is distributed to each injector. Normally, fuel injection takes place from cylinder to cylinder once every two revolutions of the crankshaft in the order of No.1, No.3, No.2 and No.4 cylinders. This is called sequential multiport fuel injection (SF1) control. When the engine is cold or it is operated under a heavy load, ECM goes to "open loop" control to enrich the mixture for maintenance of driveability. In normal operation, warm engine, the oxygen sensor signal is used to perform "closed loop" control, which controls the mixture so as to have the theoretical air fuel ratio best for purification performance of the three-way catalyst.