volume controlling unit (in-line injection pump) The volume control is achieved by a solenoid coil which is actuated by he control unit. The control travel sensor informs the control unit of the position of the control rod. description ordernumber 386 see also: speed governor of a distributor-type injection pump turbocharger with variable blade geometry air-flow sensor with fuel distributor K-Jetronic VP 44 radial-piston distributor pump