944 L4-2681cc 2.7L (1989)
THERMOSTAT VALVE
When the engine has reached a temperature of 58° C (136° F), it opens the vacuum connection from the intake manifold to diaphragm valve #1.
DIAPHRAGM VALVE #1
This valve is controlled by the thermostat valve and the throttle housing vacuum. A vacuum line is routed from diaphragm valve #1 through the
thermostat valve to the throttle housing. When the thermostat valve is open and no vacuum is applied to the diaphragm valve, the vapor hose connections
are blocked off. With vacuum at the diaphragm valve, the connection is opened and the fuel vapors can pass through it.
DIAPHRAGM VALVE #2
This valve is controlled by a vacuum line routed to the throttle housing. When vacuum is applied to diaphragm valve #2, the vapor hose connections are
blocked off. With vacuum at the diaphragm valve, the connection is opened and the fuel vapors can pass through it.
FUEL FILLER CAP
The filler cap is a non vented type to keep the fuel vapors in the gas tank system. Never replace non vented type filler cap with vented type cap.
