
"High Pressure Fuel Pump
The high pressure fuel pump is a mechanical one cylinder design driven by an additional three lobe cam on the camshaft. High pressure fuel is regulated by the fuel rail pressure (FRP) regulator, which is a part of the high pressure fuel pump. The FRP regulator is a magnetic actuator which controls the inlet valve of the high pressure pump. The ECM provides battery voltage on the actuator hi circuit and ground on the actuator low circuit. Both circuits are controlled through output drivers within the ECM. When deactivated, both drivers are disabled and the inlet valve is held open with spring pressure. When activated, the actuator low circuit driver connects the low circuit to ground and the actuator hi circuit driver pulse-width modulates (PWM) the hi circuit. The ECM uses the camshaft and crankshaft position sensor inputs to synchronize the FRP regulator with the position of each of the three camshaft lobes. The ECM regulates fuel pressure by adjusting the portion of each pump stroke that provides fuel to the rail. The high pressure fuel pump also contains an integrated pressure relief valve."

hard top see on this pic, I will try and get a better one
"The fuel injection system is a high pressure, direct injection, returnless on-demand design. The fuel injectors are mounted in the cylinder head beneath the intake ports and spray fuel directly into the combustion chamber. Direct injection requires high fuel pressure due to the fuel injector's location in the combustion chamber. Fuel pressure must be higher than compression pressure requiring a high pressure fuel pump. The fuel injectors also require more electrical power due to the high fuel pressure. The ECM supplies a separate high voltage supply circuit and a driver circuit for each fuel injector.
The fuel injector assembly is an inside opening electrical magnetic injector. The injector has six precision machined holes that generate a cone shaped oval spray pattern. The fuel injector has a slim extended tip in order to allow a sufficient cooling jacket in the cylinder head."

The JSJ is the Supercharged version of the LNF. It was used in the Cobalt's and Ion Redlines.
and I want one !