E - THEORY/OPERATION - DIGIFANT
Article Text (p. 7)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:43PM
The idle air stabilizer valve is ECU controlled. On Vanagon
idle stabilizer valve is controlled by a separate idle stabilizer
controller. The idle air stabilizer operates to continuously maintains
engine idle at a computed engine idle speed.
IGNITION SYSTEM
The Hall Effect sending unit in the distributor, uses a
shutter window wheel mounted on the distributor shaft. The shutter
blades pass in and out of the air gap of the hall effect sender
resulting in signal pulses (engine speed signal). There is one shutter
window for each engine cylinder. Signals from distributor hall sender
are sent to the ECU.
ELECTRONIC IGNITION SYSTEM
IGNITION COIL CONTROL
Signals from distributor hall sender are sent to the ECU,
which produces a pulsating signal to the ignition coil. This computed
signal from ECU to ignition coil, control ignition timing according to
engine load (airflow sensor signal), engine speed (Hall Effect signal)
and engine coolant temperature.
IGNITION TIMING ADVANCE CONTROL SYSTEM
Timing is ECU controlled.
EMISSION SYSTEMS
EVAPORATIVE EMISSIONS SYSTEM
Fuel vapors are collected in the expansion tank. Any liquid
gasoline collect in expansion tank flows back to the fuel tank through
vent lines. See Fig. 4. Fuel vapors are drawn from tops of the
expansion tanks and flow into the carbon canister where the vapors are
stored. When the engine is not running.
After engine is started, the control valve is opened by
throttle vacuum. Fresh air is drawn into bottom of the canister. Fuel
vapors from the canister are drawn into the intake manifold.
EXHAUST GAS RECIRCULATION
Information is not available. See M - VACUUM DIAGRAMS for
system components and vacuum hose routings.
