Volkswagen Type II Transporter 1200 Series Shop Manual page 59

AIR CORRECTION JET
GASKET
IDLING MIXTURE SCREW
•••. J'''"
I
·r' · ·---------
o . . _ _ _ _
MAINJET ..
~
JETPLUG
-~r
·Main Jet Components of 28 PCI Carburettor.
Also check the tapered seat on the tip of the idling
screw to ensure that it is not damaged.
{12) Instal the float and toggle lever.
TO ADJUST IDLING SPEED AND MIXTURE
The engine must be hot before idling adjustment is
attempted.
(I) Using a suitable screwdriver, tighten and slacken
the idling speed adjusting screw until the engine is idling at
approximately 550 rpm.
(2) Turn the idling mixture adjusting screw clockwise
until there is a drop in engine speed and as soon as this
happens, turn the screw anti-clockwise. Continue turning
the screw very slightly in either direction until the engine
idles smoothly.
(3) With the engine firing evenly on all cylinders,
readjust the idling speed screw until the normal idling speed
is obtained.
Fuel System-5
PLUG~
Float Needle Valve Assembly. 28 PCI Carburettors. Typical
also of PICT Carburettors.
Usually the correct idling setting is obtained by turning
the mixture control screw l
Y..
to l \6 turns from the closed
position. In no case should the screw be tightened in fully
as this is likely to damage the screw tapered point.
Accurate setting of the idling is very important as it
greatly affects fuel consumption at low speeds.
Poor idling can be caused by damaged gaskets or intake
manifold being incorrectly tightened or the fuel pump
adjustment being incorrect.
Faulty ignition system or weak engine compression can
also have an adverse affect' on the idling.
2. C.,tRBURETTOR SOLEX TYPE PICT
DESCRIPTION
Transporters from Engine No 5000001 are fitted with
the PICT Type Solex carburettor which incorporates an
automatic choke.
When a cold engine is being started, the carburettor
choke operation is automatically controlled by a heater
element and a bi-metal spring. Under normal driving
conditions, a vacuum piston, (on later models a diaphragm,)
connected to the choke shaft link and operated by the
vacuum in the manifold, ensures proper functioning of the
arrangement. A richer mixture, at full load, is provided· by .
the power fuel system.
This type of carburettor is so designed to ensure easy
engine starting in any weather and the engine performance
is improved at all temperatures. This improvement is more
59
marked at idling speeds and between idling and normal
running. A better fuel consumption is experienced with
part load and city traffic operation. With this type of
carburettor there is no provision for a choke control cable.
The mounting of the carburettor on the induction
manifold is the same as for the previous type.
The carburettor body is in two parts, the lower and the
upper, with a gasket installed between the two and five
screws attaching them together.
The upper portion of the carburettor houses the float
needle valve and the fuel delivery pipe from the fuel pump.
The float chamber vent tube is pressed into the upper
portion in which the automatic choke is also located. On
one end of the choke valve shaft and choke valve is a fast
idle cam and lever. On the other end is installed a heater
element and a bi-metal thermostat spring fixed firrnly in a