Chevrolet CHEVY VAN G10 SERIES Service Manual page 204

EMISSION CONTROL SYSTEM 6T-12
G en eral D escrip tio n
M a in te n an ce P ro c e d u re s ................................................... 6T -1 5
D rive B elt
In sp ectio n
A d ju stm e n t
R e p la c e m e n t
P u m p P ulley
R e p la c e m e n t .................................................................6 T - 16
A ir M a n ifo ld , H o se a n d T u b e
In sp ec tio n
R e p la c e m e n t
C h e ck V a lv e ( s )
The Air Injection R eactor (A .I.R .) System (Fig. 21 & 22),
used on Chevrolet passenger car engines consists of: the air
injection pum p (w ith necessary brackets and drive attach ­
m ents), air injection tubes (one for each cylinder), an air
diverter valve, check valves (one for in-line engines, tw o for V
engines) and air m anifold assemblies, and hoses necessary to
connect the various com ponents.
Carburetors and distributors for engines w ith the A .I.R .
System are designed, particularly, for these engines; therefore
they should n o t be interchanged with or replaced by a
carburetor or distributor designed for engines w ithout the
A .I.R . System .
The air injection pum p (Fig. 6T-23) with an integral filter,
compresses the air and injects it through the air m anifolds,
hoses and injection tubes in to the exhaust system in the area
o f the exhaust valves (Fig. 6T-24). The fresh air helps burn the
unburned portion o f the exhaust gases in the exhaust system,
thus minimizing exhaust contam inations.
The diverter valve (Fig. 6T-25), when triggered by a sharp
increase in m anifold vacuum (overrun), tem porarily shuts off
the injected air to the exhaust port areas and prevents
AIR INJECTION REACTOR SYSTEM
P age
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6 T -1 5
6 T -1 5
6 T -1 5
6 T -1 6
6 T -1 6
6 T -1 7
6 T -1 7
6 T -1 7
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GENERAL DESCRIPTION
INDEX
In sp ec tio n ......................................................................6 T -1 7
R e p la c e m e n t
D iv e rte r V alv e .................................................................6 T -1 8
In sp ec tio n ......................................................................6 T -1 8
R e p la cem en t
A ir In jec tio n T u b e
In sp e c tio n ......................................................................6 T -1 8
R e p la c e m e n t .................................................................6 T -1 9
A ir In jec tio n P u m p
In sp ec tio n ......................................................................6 T -1 9
P re ssu re R elief V alv e .............................................. 6 T -1 9
backfiring during this richer period.
A t high engine speeds excess air is dum ped through the
pressure relief valve which is incorporated in the diverter valve.
The check valve(s) prevent exhaust gases from entering and
8
damaging the air injection pum p, as back flow can occur even
under normal operating conditions.
When properly installed and m aintained, the A.I.R. System
will effectively reduce exhaust emissions. However, if any
A .I.R. com ponent or any engine com ponent that operates in
conjunction with the A .I.R. System should m alfunction, the
exhaust emissions might be increased.
Because o f the relationship between " Engine Tune U p" and
" U nburned Exhaust Gases," the condition o f the Engine Tune
Up should be checked whenever the A .I.R. System seems to be
m alfunctioning. Particular care should be taken in checking
item s that affect fuel-air ratio such as the crankcase ventilation
system , the carburetor and the carburetor air cleaner.
Because o f the sim ilarity o f many parts, typical illustrations
and procedures are used except where specific illustrations or
procedures are necessary to clarify the operation.
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C H E V Y V A N S H O P M A N U A L