Most of the candidates who attempted this question could not give the required responses to the various parts of the question. The required responses to the various parts of the question are:
(a)(i) The parts labelled X, V, U, V and Ware: injection pump, injector, fuel tank, lift pump and fuel filter
respectively.
(ii) The function of the parts labelled V, Wand Yare:
V - draws fuel from the tank and supplies it to the injection pump.
W - removes dirts and particles from the fuel.
V - atomises the fuel into the combustion chamber.
(b) The causes of black smoke from a compression ignition engine exhaust are:
- faulty injector nozzles or faulty injectors;
- faulty delivery valve;
-
chocked air cleaner or air filters;
- adulterated fuel;
- incorrect injector pump timing.
