Carburettor - description

1. Several types and makes of carburettor are fitted to the vehicles covered by this manual.

All are of the downdraught type.

2. The 32 TL carburettor fitted to the 1.2 engine is a fixed jet, single barrel instrument. The 35 PDSI and 1B1 fitted to low compression versions of the 1.3 engine are similar.

3. The 2E3 carburettor fitted to normal compression versions of the 1.3 engine is a fixed jet, twin barrel instrument. Opening of the throttle valves is sequential; the primary throttle valve is opened mechanically, but the secondary throttle valve is opened by vacuum developed in both venturis. Primary and secondary transition systems, and a part load enrichment valve, ensure efficient operation under all speed and load conditions.

4. The GM Varajet ll carburettor fitted to 1.6 models is also a twin barrel type, but the main fuel jet is controlled by a tapered needle valve.

The design is well proven and has been used on several earlier models.

5. All carburettors have a bypass system for providing idle mixture, and an accelerator pump for mixture enrichment when the throttle is opened rapidly.

6. When an automatic choke is fitted, the choke cover is heated electrically when the engine is running; as the cover warms up, the choke is released. On the 2E3 carburettor the choke cover is also heated by engine coolant.

Both types of automatic choke need to be 'primed' by depressing and releasing the accelerator pedal before starting the engine from cold.