the wire to the solenoid on the front of the pump, if you wire it in to your fuel shut off solenoid it will get constant power when the engine is running.
The solenoid on the front controls a bypass for the case pressure to your advance piston.
When turned on, it allows case pressure to give you advance.
when powered off it bypasses a percentage so your timing is more retarded.
They did it for emissions, so at lower power demands you have less NOx emissions.
It does have the benefit of quieter in town when light on the throttle
I found with mine, when you hardwire it. At light throttle, with the advance makes a nice nailing
I set up a boost pressure switch for mine, so when you wanna move it, timing advances and you go.
and when light coasting, under 5psi boost. It quiets things down.
Makes the seat warmer happy
Peace