Emission Control Systems; Closed P.c.v. System; Controlled Combustion System; Vacuum Advance Valve - Pontiac Grand Prix Service Manual

EMISSION CONTROL SYSTEMS
CONTENTS OF THIS SECTION
SUBJECT PAGE SUBJECT PAGE
. . . . . . . . . . . . .
Periodic Service
-
Closed PCV System.
. . .
6D-1 Motor Replacement. 6D-1
. . . . . . . . . . . . .
Controlled Combustion System.
. . . . . . . .
6D-1 Sensor Replacement. 6D-2
Thermostatic Vacuum Switch.
. . . . . . . .
6D-1 Idle Speeds and Procedure.
. . . . . . . . . .
6D-2
Auto-Therm A.C. Air Cleaner.
. . . . . . . .
6D- 1 Dwell and Ignition Timing Specifications
. . .
6D-3
SERVICE PROCEDURES
PERIODIC SERVICE
CLOSED P.C.V. SYSTEM
Once a year or at 12,000 miles, the Closed Positive
Crankcase Ventilation System should be serviced as
follows:
1. Disconnect all hoses and blow them out with
compressed air. If any hose cannot be freed of
obstructions, replace with new hose.
2. Remove crankcase ventilation valve.
3. All engines are equipped with a crimped-type valve,
thus no further disassembly is possible and a new
valve should be installed.
4. Clean crankcase and intake manifold connectors
using care not to allow dirt to enter openings.
5. Clean and re-oil ventilation filter in air cleaner.
6. Clean or replace air filter element.
7. Reinstall positive crankcase ventilation system.
8. Adjust carburetor idle to specifications.
CONTROLLED COMBUSTION SYSTEM
In order to provide eff~cient engine operation of cars
equipped with the Controlled Combustion System, all
normal tune-up items should receive careful and
thorough attention every 12 months or 12,000 miles.
Adherence to these items will assure that exhaust
emissions are kept to the desired level.
Essential services included in the tune-up items are:
1. Check engine idle speed.
2. Check ignition timing (distributor advance hose
disconnected and plugged and idle stop solenoid
inactive
-
6 cylinder and Ram Air).
3. Check operation of distributor advance unit.
NOTE: Engine idle speed must be set following the
correct procedure.
VACUUM ADVANCE VALVE (2 Bbl. Manual
Transmission Only)
No adjustments are necesiary to the vacuum advana
valve.
THERMOSTATIC VACUUM SWITCH (Automatic
Transmission V-8 Only)
No maintenance is necespary on the thermostatic
vacuum switch.
AUTO-THERM AC AIR CLEANER
MOTOR REPLACEMENT
REMOVE
1. Drill out two spot welds initially with a 1
/
16" drill,
then enlarge as required to remove the retaining strap.
Do not damage snorkel tube. (Fig. 6D-1).
2. Raise motor strap retainer.
3. Lift motor, cocking it to one side to unhook linkage
at the control damper.
1. Assemble in reverse order adhering to the following
notes.
a. Drill a 7/64" hole in snorkel tube at point A
as
shown in Fig. 6D- 1.