Modifications to the
combustion chamber, intake manifold, camshaft and ignition system form the
basic control system.
These items have been
integrated into a highly effective system which controls exhaust emissions
while maintaining good driveability and fuel economy.
AIR/FUEL
MIXTURE CONTROL SYSTEM [MULTIPORT FUEL INJECTION (MFI) SYSTEM]
This in turn allows
the engine to produce exhaust gases of the proper composition to permit
the use of a three way catalyst. The three way catalyst is designed to
convert the three pollutants (1) hydrocarbons (HC), (2) carbon monoxide
(CO), and (3) oxides of nitrogen (NOx) into harmless substances. There are
two operating modes in the MFI system.
| 1. |
Open Loop air/fuel ratio is controlled by
information programmed into the
ECM. |
| 2. |
Closed Loop air/fuel ratio is adjusted by
the ECM based on information supplied by the oxygen
sensor. |
