What is the principle of injectors PT (Type D) style on VTA28G5 Cummins Engine and What is the difference in the work between TOP STOP injector and injectors without TOT STOP Thanks?

The PT (Type D) injectors on the Cummins VTA28G5 engine utilize a plunger and barrel design that allows for precise control of fuel injection timing and volume, enhancing engine efficiency and performance. The key difference between a Top Stop injector and those without a Top Stop lies in the mechanism that prevents the plunger from traveling too far down the barrel, ensuring a more consistent injection timing and improved atomization. This results in better combustion efficiency and reduced emissions compared to injectors without the Top Stop feature.