B250 3/4 Ton Van V8-318 5.2L VIN T FI (1992)
^
The engine controller adjusts ignition timing by increasing and decreasing spark advance.
^
The engine controller operates the A/C compressor clutch through the clutch relay. This happens if A/C has been selected by the vehicle
operator and requested by the A/C thermostat.
Cruise
When the engine is at operating temperature, this is a Closed Loop mode. At cruising speed the engine controller receives inputs from:
^
Air conditioning select signal (if equipped)
^
Air conditioning request signal (if equipped)
^
Battery voltage
^
Coolant temperature sensor
^
Crankshaft position sensor
^
Charge Air Temperature sensor
^
Manifold absolute pressure (MAP) sensor
^
Throttle position sensor (TPS)
^
Sync signal (in distributor)
^
Neutral Safety switch (gear indicator signal)
^
Oxygen (02) sensor
Based on these inputs, the following occurs:
^
Voltage is applied to the fuel injectors with the engine controller adjusting the injector pulse width. This is done by turning the ground circuit
to each individual injector on and off.
^
The engine controller monitors the 02 sensor input and adjusts air-fuel ratio. It also adjusts engine idle speed through the automatic idle speed
(AIS) motor. ^ The engine controller adjusts ignition timing by turning the ground path to the coil on and off.
^
The engine controller operates the A/C compressor clutch through the clutch relay. This happens if A/C has been selected by the vehicle
operator and requested by the A/C thermostat.
Acceleration
This is an Open Loop mode. The engine controller recognizes an abrupt increase in throttle position or MAP pressure as a demand for increased
engine output and vehicle acceleration. The engine controller increases injector pulse width in response to increased throttle opening.
Wide Open Throttle
This is an Open Loop mode. During wide open throttle operation, the engine controller receives the following inputs:
^
Battery voltage
^
Crankshaft position sensor (CPS)
^
Coolant temperature sensor
^
Charge Air Temperature sensor
^
Manifold absolute pressure (MAP) sensor
^
Throttle position sensor (TPS)
^
Sync signal (in distributor)
