Chevrolet 1977 light duty truck, Service Manual

Page: 20 / 861

torque carburetor attaching bolts and/or nuts to
compensate for compression of the gasket.
C-6VACUUM ADVANCE SYSTEM AND HOSES - Check
system for proper operation and hoses for
proper connection, cracking, abrasion or deteri­
oration. Replace as necessary.
C-7 FUEL FILTER—Replace filter in carburetor at des­
ignated intervals or more frequently if clogged.
C-8 POSITIVE CRANKCASE VENTILATION SYSTEM (PCV)
—Check the PCV system for satisfactory oper­
ation at 15,000-mile intervals, and clean filter.
Replace the PCV valve at 30,000-mile intervals
and blow out PCV valve hose with compressed
air. Replace deteriorated hoses.
The PCV filter (located in the air cleaner) should
be replaced whenever the air cleaner element
is replaced.
C-9 SPARK PLUG WIRES—Clean exterior of wires; re­
move any evidence of corrosion on end termi­
nals. Inspect spark plug wires for evidence of
checking, burning, or cracking of exterior insu­
lation and tight fit at distributor cap and spark
plugs or other deterioration. If corrosion cannot
be removed or other conditions above are noted,
replace wire.
C-10 IDLE SPEED-UP SOLENOID—Check for proper oper­
ation. An inoperative solenoid must be replaced.
C-11 SPARK PLUGS—Replace plugs at 22,500-mile in­
tervals with type specified in Owner’s and
Driver's Manual.
C-12 TIMING AND DISTRIBUTOR CAP - Adjust ignition
timing following the specifications shown on
label under hood. Also, carefully inspect the in­
terior and exterior of the distributor cap and
rotor for cracks, carbon tracking and terminal
corrosion. Clean or replace as necessary.
C-13CARBURETOR VACUUM BREAK ADJUSTMENT — In­
spect vacuum break linkage for proper oper­
ation. A binding condition must be corrected.
Check hoses for proper connection, cracking,
abrasion or deterioration. Replace parts as nec-
ecessary. Adjust vacuum break at specified in­
tervals following procedure and specifications
found in appropriate service manual.
C-14 EVAPORATION CONTROL SYSTEM (ECS)-Check all
fuel and vapor lines and hoses for proper con­
nections and correct routing as well as condi­
tion. Remove canister and check for cracks or
damage. Replace damaged or deteriorated parts
as necessary. Replace filter in lower section of
canister.
C-15 FUEL CAP, FUEL LINES AND FUEL TANK—
1. Inspect the fuel tank, cap and lines for dam­
age which could cause leaks.
2. Remove fuel cap and inspect gasket for an
even imprint from the filler neck, and any indi­
cations of physical damage.
3. Replace any damaged or deteriorated parts.
C-1G AIR CLEANER ELEMENT—Replace the engine air
cleaner element at designated intervals. Oper­
ation of vehicle in dusty areas will necessitate
more frequent replacements. Your dealer can be
of assistance in determining the proper replace­
ment frequency for the conditions under which
you operate your vehicle.
CAUTION: Do not operate the engine without
the air cleaner unless temporary removal is nec­
essary during repair or maintenance of the
vehicle. When the air cleaner is removed, back­
firing can cause fire in the engine compartment.
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