Delphi E3 needle lift
A. The spill valve is electrically activated and closes; fuel is forced from the pump chamber via the high
pressure fuel line acting on the injection needle lift area.
B. The fuel pressure increases and reaches the pressure required to overcome the closing force from the
needle closing spring, but as the NCV is still open the needle can not lift.
C. The fuel pressure reaches the desired needle opening pressure.
D. The NCV is electrically activated and opens; the fuel pressure in the needle backing chamber is
evacuated allowing the needle to lift.
E. The injection needle is lifted.
F. The fuel amount required is now injected and the NCV is deactivated, closed. The needle backing
chamber is now again connected to the high pressure fuel line and the needle is forced to close.
G. The needle closes and injection ends.
H. As the SV is still closed the pressure continues to increase as long as the pump piston is moving
downwards.
I. The spill valve is deactivated, opened. The fuel is routed into the low pressure feed line.
J. The fuel pressure is evacuated to the low pressure feed line via the open SV.
Picture text:
1. Needle lift
2. Needle opening pressure, desired
3. Needle opening pressure, spring
4. Fuel pressure
5. Spill valve (SV)
6. Needle control valve (NCV)
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