GM Service Manual Online
For 1990-2009 cars only

Object Number: 27821  Size: LH
(1)Inlet
(2)Return
(3)Pressure Spring
(4)Nozzle Nut
(5)Needle Valve
(6)Pintle

Each cylinder has an identical fuel injection nozzle mounted in the pre-combustion chamber. As the pressure wave of injection reaches a nozzle, the needle valve is lifted against spring force and fuel exits into the pre-combustion chamber of the cylinder as a highly atomized spray. A small amount of fuel travels between the needle valve and pintle nozzle, providing lubrication. Two passages inside the upper half of the nozzle body allow fuel that has lubricated the needle valve to exit into the fuel return system.