eXhaust Gas recircuLation (eGr)
3) Connect the pump between the EGR valve and
the carburetor or vacuum source . Start the engine
and run it at idle until it reaches operating
temperature (195°F approx .) . Check for vacuum
at 3000 RPM; it should be 5" Hg minimum .
4) If no vacuum is available in step 3, check for it
between the EGR thermal vacuum switch (TVS) and
the carburetor . If the vac uum is available there,
replace the TVS .
5) If the vacuum supply between the EGR and the
carburetor is adequate, connect the pump to the
EGR valve inlet . Depress the valve diaphragm and
apply approximately 10" Hg vacuum to the EGR .
Release the diaphragm and record the time it takes
for the diaphragm to return to its seated position .
To Starter Relay
To Ignition
Vacuum Amplifier
EGR Delay
Timer
EGR Valve
CCEGR Temperature Valve
FIGURE 10: CHRYSLER VENTURI VACUUM-CONTROL EGR SYSTEM
Form 824426
6) If it takes less than 20 seconds for the valve to
seat, replace the valve .
GM POSITIVE BACKPRESSURE EGR TEST
1) Follow steps 1 through 4 of the ported vacuum
and negative back-pressure EGR test .
2) Remove the EGR valve from the engine .
Connect the pump to the EGR vacuum inlet and
apply 10" Hg of vacuum . The valve should not
open . If it does, replace the valve .
3) Continue the test by keeping the vacu um applied
and shooting a low-pressure stream of air into the
valve's exhaust inlet . The valve should now open .
If it does not, replace the valve .
EGR Delay
Solenoid
Coolant Control Engine Vacuum Switch
Manifold Vacuum
Page Number - 15