TL960 SERVICE MANUAL
End of Injection:
The end of the injection cycle begins when the ECM terminates the electric pulse to the solenoid. The following events occur: The magnetic field of the solenoid collapses and is no longer able to overcome poppet spring tension to hold the poppet off its seat. The poppet closes, shutting off high pressure oil from entering the injector. When the poppet is seated, the upper land of the poppet opens the poppet cavity to drain. Pressurized oil in the intensifier chamber and poppet chamber flows upward around the poppet seat, through the vent holes in the poppet sleeve and out the adapter drain hole. The pressure of the fuel in the plunger cavity exerts an upward force on the plunger and intensifier. As the pressure of the pressurized oil above the intensifier drops, so does the downward force on the intensifier.