The pump plunger 43 is reciprocated by a cam 111 on the camshaft (110, Fig. 5) operating the engine inlet and exhaust valves and the pump is located in the engine valve gear cover 100 or the cylinder head (130, Fig. 7). The timing of pump delivery to an accumulator rail is determined by closing of a solenoid-operated valve 23 at one end of the plunger bore 16. Two pumps 10 may supply respective engine cylinders. The plunger tappet 41 or the plunger 43 may be directly guided in the valve gear cover (Figs. 9 and 17). <IMAGE>
