17
Fuel System and Carburettor
Fuel System
The fuel system consists of the fuel tank, line and filters, mechanical pump, carburettor and air
cleaner.
Fuel Tank
The fuel tank is located below the floor of the boot and has a capacity of 16 gallons Imp., 19 gallons
(U.S.) or 72 litres. The low fuel warning light in the face of the rev counter burns continu-ously when
3 gallons or less remain in the tank.
The fuel tank filler pipe is covered by a flap on the left hand rear wing, which can be opened
automatically from the driver’s seat. The ‘Re-fuel’ switch on the facia controls a solenoid which,
when energised, allows the flap to fly open. Alternatively the flap can be opened manually by depressing
the small plated lever in the top left hand corner of the boot. There is a drain plug in the bottom of the
tank.
Fuel Line and Filters
The fuel line incorporates two filters, one before and one after the fuel pump. These are of the paper
cartridge type and cannot be cleaned. The filter between the tank and pump should be replaced every
20,000 miles and the filter after the pump every 80,000 miles.
Note:
Where dirty petrol has been
used, more frequent filter changes will be necessary.
Fuel Pump
The mechanical fuel pump is located on the right hand side of the engine. It is driven from the
camshaft and delivers fuel to the carburettor at 3-1/2 p.s.i.
Carburettor
The Carter AFB (Aluminium Four Barrel) carburettor is a compli-cated and sensitive instrument, for it
combines the best features of both single and multi-choke designs in one unit.
All jets etc. are correctly set before installation, so the only adjustment normally necessary will be to
the idling speed settings.
Idle Speed Adjustment—(Curb
Idle)
To make the idle speed adjustment, the engine must be thoroughly warmed up. A much more reliable
idle adjustment can be obtained if the car has been driven a minimum of five miles. For the best
results, it is recommended that the tachometer be used in this adjustment.
Before making the idle speed adjustment observe the following precautions :
(
1)
On cars equipped with the automatic transmission, disconnect the carburettor to bellcrank rod so that
the stop in the transmission will not interfere with the free movement of the carburettor throttle lever.
(2)
To make the idle speed adjustment proceed as follows :—
(i) Turn the idle speed screw
in
or
out
to obtain 500 r.p.m. Be sure the choke valve is fully open and
that the fast idle adjustment screw is not contacting the fast idle cam.
(ii)
Turn each idle mixture screw to obtain the highest r.p.m. While making the adjustment, carefully
watch the tachometer and notice that the speed can be decreased by turning the screws in
either direction from the setting that gave the highest r.p.m. reading.
(iii)
Readjust to 500 r.p.m. with the idle speed screw.
(iv)
Turn each idle mixture adjusting screw in the clock-wise direction (leaner) until there is a slight
drop in r.p.m. Now, turn each screw out, counter-clockwise (richer), just enough to regain the
lost
r.p.m.
This procedure will assure that the idle has been set to the leanest possible mixture for smooth
idle.
This setting is very important!
Since the correct speed was originally set using the speed screw, the speed obtained after
finding the leanest smooth idle setting will probably be too fast.
( v )
Readjust the speed screw to obtain correct idle speed. Repeat steps 2 and 4 above if necessary.
After the proper idle speed has been obtained, check transmission setting as described under throttle linkage.
Fig. 7.
