Truck Repair: m11, celect, injector system

Question
What is the difference between celect and stc. In order to set the valves and injectors. ISM 370

Answer
Celect is simply a system developd by Cummins to electronically manage an engine. it consists of an ECM (Electronic control module) solenoid actuated injectors and a network of sensors.
STC is a step timing control injector system that employs the use of oil to power assist in operating the injectors to advance the injection timing and hence improve exhaust emission.

Celect injectors are adjusted 2 flats, while STC follows the normal system of zero setting with the additional usage of a special tool to hold the injector in place to prevent preloading during zero setting.

Please refer to your cummins shop for more details.