This document provides an overview of the 1.9-liter TDI engine with pump injection system used in Volkswagen vehicles. It describes the key features and modifications made to the engine, including the use of a trapezoidal piston and connecting rod to handle higher combustion pressures, and changes to the toothed belt drive to reduce load. It also summarizes the pump injection system, which can achieve very high injection pressures, and precisely control injection timing and quantity for improved performance and reduced emissions. The fuel supply system is outlined, including the mechanical fuel pump, fuel lines, filter, cooler and sensors.