Chevrolet 1963 Corvette, Руководство по ремонту и настройке

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EMISSION CONTROLS AND FUEL SYSTEM 147
detonation sensor, the entire computer emis-
sions system should be professionally tested.
Because both types of EST systems are di-
rectly tied into the computer emissions sys-
tem, service, testing, and repair should be
performed by a qualified, professional tech-
nician.
FUEL SYSTEM
Mechanical Fuel Pump
The 1963-81 Corvette fuel pump is a me-
chanically operated diaphragm-type pump.
The camshaft of the engine has an eccentric
(similar to a cam lobe, but more rounded) cast
as part of the camshaft. As the camshaft ro-
tates, the eccentric actuates a pushrod which
pushes the fuel pump rocker arm to activate
the pump.
The fuel pump is attached to the right front
of the cylinder block. On small-block en-
gines, a fuel pump mounting plate is used,
with two gaskets; one between the pump and
the plate; the other between the plate and
the block. Pumps on big-block engines attach
directly to the block and use only one gasket.
The inlet, or suction line of the pump,
draws fuel from the tank. The outlet, or pres-
sure line of the pump, supplies pressurized
fuel to the carburetor (or fuel injection unit,
in early Corvettes). Some models use a third
line, which is a vapor return. The purpose of
the vapor return is to route the hot fuel and
fuel vapor from the pump back to the fuel
tank, which considerably reduces the chance
of vapor lock.
For all intents and purposes, the fuel pump
is not rebuildable. Some '60s Corvettes used
a rebuildable pump, though parts for these
pumps are no longer available from Chevro-
let.
REMOVAL AND INSTALLATION
1. Disconnect the fuel inlet, outlet, and
vapor return (if equipped) lines from the
pump.
2. On small-block engines, remove the bolt
from the front right face of the engine block
which is almost opposite the forward pump
mounting bolt. Insert a longer bolt (%x!6x2
in.) in this hole and snug down the bolt. This
will hold the fuel pump pushrod in place. On
big-block engines, the pushrod can be re
tained with heavy grease or mechanical fingers
during installation.
Typical 1963-81 mechanical fuel pump mounting
(1974 350 shown)
3. Remove the fuel pump mounting bolts
and remove the fuel pump.
4. Installation of the pump is the reverse
of the previous steps. Replace the fuel pump
gasket(s) during installation. Start the engine
and check the pump for proper operation, and
check for leaks.
TESTING
If the engine exhibits a tendency to "starve-
out", never assume that the fuel pump is de-
fective until you test the pump. In most cases,
a "starve-out" condition is caused by a weak
ignition system, plugged fuel filter, or re-
stricted fuel line. 1. Disconnect the fuel
line from the car-
FITTING
PUMP ASSEMBLY-
FUEL
VALVE ASSEMBLY
ELBOW