Emission Controls. Before beginning to understand emission controls you should know the reason why emission controls were installed into the automobile. 1. To reduce the amount of pollutants entering the atmosphere . . Emission Controls. Smog is a term developed from smoke and fog
1. To reduce the amount of pollutants entering the atmosphere .Emission Controls
All petroleum products and made of hydrocarbons (hydrogen and carbon compounds) this includes:
Diesel motor oil.Exhaust Gasses
Hydrocarbons emission is considered a hazardous form of air pollution because of.
And possibility cancer.Exhaust Gasses
HC 220 ppm
14.7 – 1 AFR
Hc and Co decreases
Thermostats are now 190 degrees
Wider spark plug gap
Some are .080 thousands
When engine Vacuum is High
PCV valve plunger is nearly
When engine vacuum is low plunger
Opens. Allowing exhaust gasses into
The EVAP system prevents Hydrocarbons in the form of fuel vapors from entering the atmosphere even when the vehicle is not running.
An EVAP system is considered a closed system.
Fuel vapor are stored in a charcoal canister when the engine is off.
Intake Manifold Vacuum
Fuel Tank Pressure Sensor
EGR Control Solenoid PCM Controlled
To EGR valve
Vacuum off throttle
Exhaust Gasses to Engine
Throttle Position Sensor
Vacuum present when Solenoid open by PCM
12 from ignition
Ports to Intake manifold
2.Technician A says that a PCV valve is used to remove blow-by from the crankcase. Technician B says the PCV valve is used to prevent HC from being vented into the atmosphere. Who is correct?
A Both A and B B. Neither A nor B
C. A only D. B only
3. Technician A says that the EGR valve should operate at idle with the engine cold. Technician A says the EGR flow should increase combustion chamber temperature. Who is correct?
HC and CO
Exhaust Flow from engine through converter
CO, HC and NOx
CO2 and H20