The adjustment of the start of fuel delivery of a piston internal combustion engine has hitherto been complicated and relatively inaccurate. The solution consists of a device with an electronic angle of rotation measuring instrument with digital display, which before measurement on the engine is zeroed in to the top dead centre position of the cylinder (1) by means of a master plate and which on the engine engages without play in a bore (11) of the crankshaft end (20) and in a bore (9) of the crankcase (10). The invention is suitable for all piston internal combustion engines with injection pump. <IMAGE>
