The object of all of the systems is to maintain theoptimum air/ fuel mixture, which is chemically correctfor theoretically complete combustion.The stoichiometric ratio is 14.7 :1 (air to fuel).
Fuel inlet system. Cold start system. Idle system. Main metering system. Power enrichment system.
The need for Better fuel economy The increasingly strict emission control regulations Dictate a more exact control of the engine air/fuel mixture These systems operate in the following manner: The oxygen sensor, installed in the exhaust manifold upstream of the catalytic converter, reads the oxygen content of the exhaust- gases. It generates an electrical signal and sends it to the computer The computer then decides how to adjust the mixture to. keep it at the correct air/fuel ratio.
RICH MIXTURE AMOUNT OF OXYGEN IN EXHAUST. LOW PRESSURE UNDER DIAPHRAM HIGH SENSOR VOLTAGE DECREASING FREQUENCY VALVE FREQUENCY VALVE OPENCLOSE RATIO OPENCLOSE RATIO DECREASING INCREASING PRESSURE UNDER DIAPHRAMLOW SENSOR VOLTAGE INCREASING AMOUNT OF OXYGEN IN EXHAUST .HIGH LEAN MIXTURE
FUEL CONTROL SYSTEM ENGINE EXHAUST THROTTLE OXYGEN BODY SENSOR RETUR N LINE PRESSURE CATALYTIC REGULATOR CONVERTER ELECTRONICFILTER CONTROL UNIT FUEL TANK M. E. V. P S S E.
Conventional Ignition System is triggered by contact breakers The ignition coil is switched on and off mechanically Synchronization with the crankshaft The centrifugal advance mechanism adjusts the ignitiontiming in relation to engine speed. The vacuum advance mechanism adjusts the ignitiontiming in relationship to engine load.
Transistorised Ignition Triggering is done by transistors. Ignition advance is the same as for the conventional.
Fully programmed Electronic IgnitionThere is no mechanical advance system in the distributor.Engine speed and proximity sensor is used to triggerthe ignition.The E.C.U. computes the required ignition point and modifies theoutput signal.
Fully programmed Electronic Ignition An ignition advance map is written into the E.C.U. It permits the best ignition point for any engine speed and load.
Static Ignition The Static Ignition performs the same functions as theprogrammed system but has no rotating H.T. distribution system. A four spark ignition coil is used instead of an ignitiondistributor
Static Ignition The two coils, within the four-spark ignition, are energisedalternately via the E.C.U. Ignition output stage, at the correct point for a givencylinder, determined by the E.C.U. ignition map The respective coil generates two sparks simultaneously One fires on the power stroke of the cylinder The other at the end of the exhaust stroke of the cylinder.
The Motronic fuel injection system combines the digitalcontrol of individual systems such as fuel injection and ignitioninto a single unit. From the inputs engine speed (rpm), crankshaft positionand temperature (engine and ambient air)) the control unitdetermines the ideal spark advance and fuel quantity In this manner, spark advance and fuel quantity is tailoredexactly to the engine operating conditions such as idling, partload, full load, warm up, deceleration and transient modes.