It function??

Is this correct...........when the ignition is switched on, power is feed to the amal valve powering it into the 'non vent' position?If the boost level exceeds set limit power is cut via a signal and the amal valve returns to the vent default position??

Been wondering this because whilst my boost is strong, i have a spike then the boost drops off more than expected hence losing power.I'm stage 3 spiking at 25 psi, then boost drops off to around 18 psi.First consideration is actuator, but also whilst my amal valve does have an ignition feed it does not 'click'(ignition on or off) i assume it's not working hence venting off the boost pressure???? I'm running a T34. Regards Al.