Oldsmobile 1970 Ninety-Eight Owner's Manual page 39

I:vaporation Control
System
(Required Only in California)
General Motors vehicles sold in California are equipped with an
Evaporation Control System. This system
is
designed to minimize
:he escape of fuel vapors to the atmosphere. Included in the system
!ue a special fuel tank, liquid-vapor separator, carbon canister, can-
ister purge hoses, and carburetor modifications. Fuel vapors which
f ould otherwise escape to the atmosphere are directed into the
carbon canister. The carbon adsorbs the vapors and stores them. The
rap~r
is removed from the canister during periods of engine operation
!is manifold vacuum draws the vapors into the engine and bums them.
~he
Evaporation Control System requires only periodic canister filter
~ervicing.
See service recommendations.
r-OTE: The General Motors Evaporation Control System is designed
to control evaporation losses from ),our car under all nonnal conditions
bsing 9 lb. Reid Vapor Pressure fuel specified by California test
fequirements. However, if you should use fuel of abnormally high
yolatility for existing temperature conditions, you may detect a gaso-
line odor during or after driving in heavy traffic. If you find this
~bjectionable,
you may obtain relief by using a lower volatility fuel.
B-4
for
Cleaner Air
-
Better Engine
Performance
-
follow These
Periodic
Servi ce
Recommendations
Interval System Se rvice
At first o il chang. -
Positive Crankcase Check for prope r ope ration
4 mos. or 6,000 miles Ven tilation (PCY)
(whichever occurs
Set idle speed a nd
ig nition
fir st)
Control led
Combustion timing
10
specifications on
System «((5) decol under hood.
At
every
other oil Positive Crankcase
Cleon and reoil CTa nkc:o se
change-8 mos, or Ve ntilation (PCV)
ventilation filte r.~
12,000 miles (which.
ever comes f irst )
Po sit ive- Cran kca se Re place- PCV valve. Inspe-ct
Ventila t ion (PCV) all hoses, fittings and inlet
a ir fi lter. Replace- or clean
as neces$Ory."
Controlled Set idle speed and ignit io n
Every 12 mos. o r
Combustion tim ing to specifications on
12,000 miles (which-
System (CCS) decol under hood.
U
ever occurs fi rst)
Eva poratio n Replace fitter
;n
base
of
Control
cani ste r o nd in spect
ca n·
Syste m ister.·
NOTE: Never replace N ol
ta nk
"' .
with other thon
the specified cap.
·Service f ilters more freq uently und e r d usty conditions.
··These ad ju stme nts a re a lso included a s pa rt of the q ua lity tune-up
,
ecommended a
t
the- int
same ervals.