Volkswagen Type II Transporter 1200 Series Shop Manual page 64

1 0-Fuel System
I
CARBUR~TTOR
BODY
~
MAI~JEr-QJJ
JET PLUG
Main Jet and Idling Mixture Screw on 30 PICT-2
Carburettor.
TO ADJUST IDLING
It may be necessary to adjust the idling occasionally
but this must only be done when the engine is at operating
temperature.
NOTE: Ensure that the idling speed screw is no longer
resting on any of the steps on the fast idle cam.
(I) By means of the idle speed adjusting screw, set the
engine idling at 550 rpm.
(2) Using a screwdriver, turn the mixture control screw
in a clockwise direction until the engine speed slows down
and then turn the screw anti-clockwise
~
to 1/3 turn.
(3) Slowly turn the screw in either direction, as
required, to regulate the idling speed.
The normal initial mixtun.: can be set by turning the
mixture control screw 1
~
to 1
)6
turns from the fully closed
position. Do not tighten the screw excessively as it is likely
to be damaged. It is very important to set the idling
accurately.
PRE-IGNITION IN ENGINES
In some countries the qualities of fuels vary
considerably.·. Having a somewhat lower pre-ignition
temperature, pre-ignition can take place in the engine,
especially in the following conditions:
(I)
Wrong setting of carburettor idling, being too rich.
(2) Check and re-set ignition timing if necessary.
(3) Check adjustment of cooling air throttle ring, when
fitted.
(4) Accumulation of excessive carbon deposits in
combustion chambers.
li4
(5) Cooling of the engine insufficient due to improper
fan belt tension and excessive dirt on the outside of the
engine assembly.
In some cases where it is not possible to deal
satisfactorily with pre-ignition troubles by normal work-
shop means, a special pilot jet with electro-magnetic
shut-off valve is serviced.
TO INSTAL ELECTRO-MAGNETIC SHUT-OFF VALVE
(1)
Take out the standard pilot jet and in its place
instal the pilot jet with electro-magnetic shut-off valve.
(2) Attach a 16" connecting cable to the terminal of
the pilot jet with the electro-magnetic shut-off valve and
also the terminal 15 of the ignition coil.
By switching off the ignition, the jet needle which is
operated by an electro-magnet, obstructs the flow of fuel
by closing the pilot jet. By this means pre-ignition is
practically eliminated. When the ignition is switched on, the
jet is once again open.
The electro-magnet can be switched off by turning the
hand lever. When the handle of the lever points towards the
fan housing, the pilot jet with electro-magnet shut-offvalve
is switched on. In the opposite position it works like an
ordinary pilot jet.
Remove the jet piece from the housing when required
to be cleaned otherwise no other maintenance is necessary.
AUTOMATIC CHOKE.
AUTOMATIC CHOKE
THROTTLE SHAFT AND LEVER
ACCELERATOR PUMP
LINKAGE AND LEVER
ELECTRO-MAGNETIC SHUT-OFF VALVE FOR PILOT JET
30 PICT-2 Carburettor fitted to 1600 Models Showing
Right Hand Side. Typical also of 1500 models.