The Delphi common rail (CR) 2 pin fuel adjustment shim is a critical calibration component used in Delphi diesel injectors, operating with precision under high pressure to help maintain stable injection pressure. It ensures accurate control of the fuel quantity injected at full throttle, significantly contributing to stable high-speed engine operation, enhanced performance, and improved emission values. This specialized shim is used exclusively in heavy-duty (truck) engines and is a standard component in Delphi common rail systems. To meet the requirements of high surface quality, superior wear resistance, and precise measurement accuracy, it is manufactured with tight tolerances using a high-precision lapping process.