Lesson 4/Learning Event 2
FIGURE 65. PCV SYSTEM.
When the intake manifold vacuum is high, too much of the vapors will be drawn into the manifold and will
dilute (thin out) the fuel-air mixture coming from the carburetor if some steps are not taken to prevent it. This
would cause a loss of power. To prevent this, a ventilator valve is located in the tube close to the intake