Egr Port Locations-Typical; Snorkel Passage Open And Closed; Thermometer Check Of Sensor; Vacuum Motor - Pontiac TRANS AM 1977 Service Manual

EMISSION CONTROL SYSTEMS
6E-17
4 CYLINDER
4479
- - --
Fig. ~ E - ~ ~ E G R P O ~ ~ Locations
-
Typical
OUTSIDE AIR
DAMPER DOOR
Fig. 6E-27 Snorkel Passage Open
5. The system is operating normally as described above.
If the air cleaner fails to operate as above, or if correct
operation of the air cleaner is still in doubt, proceed to the
thermometer check (of sensor).
THERMOMETER CHECK OF SENSOR
1. Start test with air cleaner temperature below 77°F.
(25°C.). If engine has been run recently, remove air cleaner
and place on bench (this will help quickly cool the air
cleaner). Remove air cleaner cover and place Thermometer
as close as possible to the sensor. Let air cleaner cool until
thermometer reads below 79°F. (26°C.) about 5 to 10 minutes.
Reinstall air cleaner on engine and continue to step 2 below.
2. Start and idle engine. Damper door should move to
close the snorkel passage immediately if engine is cool
, -OUTSIDE AIR
/I
BLOCKED VACUUM
Fig. 6E-28 Snorkel Passage Closed
enough. Fig. 6E-28. When damper door starts to open the
snorkel passage (in a few minutes), remove air cleaner cover
and read temperature gage. It must read 123"F., plus or minus
zoo
(40"C.f 6").
3. If the damper door does not start to open up the
snorkel passage at temperature indicated, temperature sensor
is malfunctioning and must be replaced.
VACUUM MOTOR
Removal (Fig. 6E-29)
1. Remove air cleaner.
2.
Disconnect vacuum hose from motor.