Early Fuel Evaporation Systems; Valve Controlled Efe; Exhaust Gas Recirculation Systems; System Functional Test - Pontiac TRANS AM 1977 Service Manual

6E-14 1977 PONTIAC SERVICE MANUAL
CANISTER
-
F U L L MANIFOLD VACUUM
PORTED VACUUM
I
TANK
PURGE
DISTRIBUTOR
/
I
EFE-TVS
EGR-TVS
EFE VALVE ACTUATOR
3586
Fig.
6E-23 V8-305 C.I.D., VIN Code
U
DIST
=
FULL MAN1 FOLD VACUUM
-PORTED VACUUM
EARLY FUEL EVAPORATION
SYSTEMS
ORIFICE EFE
The orifice EFE system does not require periodic service.
If the orifice located in the exhaust crossover pipe becomes
loose and rattles it can be re-welded into the pipe. If the orifice
is cracked or broken making a weld repair impractical, it will
be necessary to replace the exhaust crossover pipe.
VALVE CONTROLLED EFE
/
E F E VALVE ACTUATOR
AIR PUMP
3585
Fig.
6E-24 V8-350 C.I.D., VIN Code
L
ON-CAR SERVICE
The operation of the EFE valve is to be checked at
regular maintenance intervals (refer to Section 0 for
maintenance interval information). Before performing the
following EFE valve functional test, the vehicle should be
allowed to cool down so that the engine temperature is below
40°C. (105°F.).
1. Locate EFE valve and note position of the actuator
arm.
2. Observe EFE valve when engine is started.
Valve should close when engine is started cold. The
actuator link will be pulled into the diaphragm housing.
3. If valve does not close, remove hose from EFE valve
and apply an external vacuum source in excess of 8 inches.
Valve should close.
a. If valve does not close, the valve could be seized.
Lubricate with manifold heat valve lubricant, part number
1050422, or equivalent or replace as required.
b. If valve closes, the problem is not the EFE valve.
Check for loose, kinked, pinched, plugged or cracked vacuum
hoses and connections, and repair as required. Check
function of EFE TVS. Then proceed with function test.
4. Warm up engine to normal operating temperature.
5. Observe EFE valve to see if it has opened. Valve
should open.
6. If valve does not open, remove hose from EFE valve
to see if it will open. Valve should open. If valve opens, there
is no air bleed for the diaphragm, the TVS plunger is stuck
in the cold mode or the engine is not reaching proper
operating water temperature. Replace thermostat. Replace
TVS.
EXHAUST GAS RECIRCULATION
SYSTEMS
SYSTEM FUNCTIONAL TEST
1. Initial preparation.
a. Remove air cleaner so EGR valve diaphragm
movement can be observed or felt.
NOTE: When air cleaner is removed, it is recommended
that the choke secondary vacuum break TVV be
unclipped and removed from the air cleaner body rather
than removing hoses.
b. Plug air cleaner vacuum fitting.
c. Connect a tachometer.
NOTE: On engines with an EGR-TVS, there should be
no EGR valve movement below the calibration
temperature. If there is, replace TVS.
d. Warm up engine to operating temperature.
2. Open throttle part way and then release.
3. Observe the EGR diaphragm for movement.
The valve should open slightly when the throttle is
opened and close when it is released.