The KSB introduces a new fuel line (1), Figure 2, which routes fuel from the relief port (2) of the pressure regulator
valve (3) to a pressure holeing valve (4), bypassing the normal return passage (6), Figure 1.
The pressure holding valve (4), Figure 2, is closed when the engine is cold. When the engine starts, the pressure
regulating valve (3) attempts to regulate fuel pressure as before (without KSB) but the fuel from the relief port (2)
now meets a โdead endโ at the closed pressure holding valve (4). This action hydraulically locks (closes) the pressure
regulator slider valve (4), Figure 1.
Housing pressure (5), Figure 2, is not regulated because the pressure regulator valve (3) is inoperable and so the
pressure continues to increase. This action fully advances the timing. The timing remains fully advanced until the
pressure holding valve (4) is opened.
The pressure holding valve (4), Figure 3, is opened by the expansion of an internal wax pellet (6). When the wax
pellet expands, it causes the pin (7) to extend and open the pressure holding valve (4). The wax pellet is expanded
by a resistance heating element. This element is wired to the shut down solenoid valve (8) and receives current
when a thermal switch (9) in the engine block is closed. This switch actuates at 1.60ยฐ F.
Fuel from the relief port of the pressure regulating valve now has a drain path (10) through the pressure holding
valve (4) (which is now open) to an alternate drain. The pressure regulator valve resumes normal operation and
the injection timing is regulated accordingly.
