Volkswagen Type II Transporter 1200 Series Shop Manual page 60

6-Fuel System
FAST IDLE CAM CHOKE SHAFT AUTOM~TIC
CHOKE
VACUUM ADVANCE PIPE THROTTLE LEVER
Solex 28 PICT Carburetor.
ceramic plate secured by a retainer ring and three screws in
a housing which forms an integral part of the carburettor.
There is a cylinder cast on this same housing containing a
sliding vacuum piston connected to the choke valve shaft. A
passage connects the cylinder to the vacuum below the
throttle valve. Commencing with the 28 PICT-1 carburettor
the vacuum piston was changed to a diaphragm type
vacuum control mentioned previously.
The lower portion of the carburettor houses the mixing.
and float chambers, the float and connected parts necessary
for providing the air-fuel mixture. The carburettor is
mounted on the induction manifold and is secured in
position on two studs in the lower flange. Located below
the mixing chamber are the throttle valve and shaft which
are operated by the throttle lever. The accelerator pump is
located in a housing on the side of the float chamber and is
connected to the throttle valve shaft by a lever and a
connecting rod. The float and needle valve maintain the
level of the fuel in the carburettor. The automatic choke
located in the upper portion of the carburettor facilitates
engine starting and also controls the preparation of the
fuel-air mixture required for idling and driving while the
engine is cold and till it warms up. to the normal operating
temperature.
A calibrated power fuel tube is pressed into the
carburettor cover just above the choke valve and is
connected by a drilling to the float chamber. The tube ends
above the discharge arm in the area of reduced vacuum.
At low or medium speeds, vacuum is not sufficiently
high to draw fuel from the power fuel tube, consequently
the system only comes into operation at higher speeds and
vacuum.
The idling circuit of the carburettor regulates fuel-air
mixture when the throttle valve is nearly closed. Enriching
or weakening the fuel-air mixture is done by the volume
control screw. The idle speed adjustment screw controls the
idling speed of the engine.
The improved design idling stop segment on the fast
idle cam ensures the correctness of the idling speed with the
choke valve position from the time the engine starts until it
reaches normal operating temperature.
Pre-heating the intake prevents condensation of fuel
vapor and also helps to create a readily combustible
mixture.
TO REMOVE
(I)
Disconnect the pre-heater connection of the oil
bath air cleaner intake tube.
(2) Undo the mountings and remove the oil bath air
cleaner and the elbow.
(3) Disconnect the fuel line connecting the fuel pump
to the carburettor.
(4) From the heater element, disconnect the push-on
connector.
TOP COVER
SCREWS AND WASHERS
BI-METAL SPRING AND HEAT ELEMENT
Automatic Choke Components on 30 PICT-2 Carburettor.
60