Electrical/Vacuum Solenoid; Thermal-Controlled Vacuum Switching Valves - Mityvac Silverline Elite MV8500 Manual Del Usuario

SERVICE PROCEDURES
1) Disconnect vacuum and electrical connectors from
the solenoid . Connect the pump to port "B" and
attempt to apply vacuum with pump . Vacuum
should be released through port "A" (FIGURE 14) .
) Using jumper wires, connect negative solenoid
terminal to ground and apply 1 volts to the
positive terminal . Apply vacuum to port "B" .
Vacuum should hold and not bleed off . If the
solenoid does not hold vacuum, replace solenoid .
3) With solenoid still energized, move vacuum
pump to port "A" . Attempt to apply vacuum .
Vacuum should be released through the air filter
and no vacuum should be present at port "B" .
thermaL-controLLeD vacuum-switchinG vaLves
SERVICE PROCEDURES
These control valves are called Ported Vacuum
Switches (PVS) when used on Ford engines . Thermal
Ignition Control (TIC) valves when used on Chrysler
products, and Distributor Thermal Vacuum-Switches
(DTVS) when used on General Motors engines .
The two-port valve is used to stop EGR while the
engine is cold . This type of thermal switch is needed
to provide good drivability by limiting the entrance
of EGR until the engine is warmed up .
The three-port valve is commonly called a cooling
system PVS because it switches the vacuum source to
the distributor from ported to full intake vacuum .
Color Coolant Above
Code Temperature
Green 68°F
Black 100°F
Plain or Blue 133°F
RESULTS:
No Vacuum Replace the PVS valve
Vacuum PVS valve is open
Vacuum when Replace the
coolant is cold PVS valve
FIGURE 15: TESTING THE TWO-PORT PVS
Page Number - 18
eLectricaL /vacuum soLenoiD
1) Remove both hoses
from valve
Color code
4) Operate the engine
until the coolant warms
above the valve setting (see table)
Port "A"
Positive Terminal
FIGURE 14: TYPICAL VACUUM SOLENOID
The four-port valve has been used in some Ford
engines to bypass the spark delay valve and cut
out the EGR system when the engine is cold .
SERVICE PROCEDURES
Follow this procedure to test the two-port
vacuum-switching valve:
1) Apply 10" Hg of vacuum to the bottom port of
the valve with your vacuum pump and measure the
results with a second vacuum gauge as shown in the
accompanying illustration (FIGURE 15) .
) The valves are color-coded and the green valve
should open and pass vacuum at 68°F, the black
valve at 100°F .
3) Apply 10 inches
vacuum to the valve
5) See if there is a
vacuum reading on
this gauge
) Connect a vacuum gauge
to one port and a remote
vacuum supply to the other
Air Filter
Port "B"
Form 8433