F 350 4WD Pickup V8-7.3L DSL (1988)
VACUUM RESTRICTOR (VREST) - Used to control the flow rate and/or timing inactions to different emission control components.
VACUUM RETARD DELAY VALVE (VRDV) - A valve which delays a decrease in vacuum at the distributor vacuum advance unit when the source
vacuum decreases.
VACUUM VENT VALVE (VVV) - Controls the induction of fresh air into a vacuum system to prevent chemical decay of the vacuum diaphragm that
can occur on contact with fuel. The 12A226 (natural cap) is a combined vent and delay valve. Although this valve was intended for use in a specific
system with an air cleaner mounting, it may be used in any other vacuum system and mounted elsewhere. The valve should be mounted, as shown, with
ports pointing downward for fuel drainback. The vacuum source must be connected to the cap port and the system or device operated, to the body port,
as shown.
Vane Air Temperature
VANE AIR TEMPERATURE (VAT) - A sensor located in the vane airflow meter which senses the temperature of the air flowing into the engine.
Changes of temperature result in changes in a resistive element in the sensor.
Vane Airflow Meter
VANE AIRFLOW METER (VAF) - A sensor with a movable vane connected to a potentiometer calibrated to measure the amount of air flowing
through the sensor. The output signal is relayed to the ECA which then translates the information into the amount of air flowing into the engine.
VANE METER (VM) - See "Vane Airflow Meter."
VANE TYPE DIFFUSER - Designed so the leading edge will be in line with the direction of the air flow from the impeller. The vane curvature will
force air to flow or be slowed down as required for the specific engine application. This design allows for a high peak efficiency.
VAPOR-RECOVERY SYSTEM - See "Evaporative Emission Controls."
VEHICLE BATTERY VOLTAGE - VBAT
Vehicle Emission Control Information Decal
VEHICLE EMISSION CONTROL INFORMATION DECAL (VECI) - Critical specifications for servicing emission systems. Decal located in engine
compartment.
VEHICLE SPEED SWITCH (Courier) - Attached to speedometer to help control air/fuel mixture at cruising speed.
VENT VALVE VACUUM DELAY Delays vacuum to the distributor through a sintered disk.
