Cold Start; Thermal Switch - CITROEN CX 2000 Repair Manual

COLD START INJECTOR
When the engine is cold, fuel settles on the inlet distribution chamber, and on the cylinder walls. Therefore, the
quantity of fuel which mixes with the inlet air is smaller than in an engine which has reached normal running
temperature. The mixture thus obtained will not ignite.
The cold-start injector enriches the mixture in each inlet duct by vaporizing fuel in the inlet manifold. However,
it only comes into operation when the starter motor is actuated, and when a thermal switch located inthe engine
coolanthas simultaneously closed the circuit.
'A helicoidal spring compresses the mobile core of,the electro-magnet and its seal fuel cannot pass through.
When the magnetic core is attracted, the injector seat is freed-off, the fuel flows past the core. and.reached the
spiral effect injector, which injects the fuel, simultaneously giving it a spiral motion, and vaporizing it very finely.
'THERMAL SWITCH
The thermal switch cuts out the operation of the cold-start injector when the temperature of the engine reaches
ir 35" C,,For any temperature below t 35' C, the thermal switch limits the duration of injection. The maximum
duration is approximately 7.5 sets.
at - 20' C. Duration of injection is reduced as temperature increases
The variation in duration, determined by the thermal switch,.is obtained by means of a bi-metallic strip heated
by an electrical resistance. The bi-metallic strip cuts out the circuit according to the temperature reached after
it has heated for a certain amount of time.