A notation to respond to your vac reply:
Don't expect a full vac from the purge when it is demanded...they are pulsed for just that reason.
The freq from the ECU command is from 5-20 htz., depending on engine load criteria...they do this so there is not a large Gulp of air hitting the intake all at once, effecting a/f mixture controls.
__________________
A Dalton
|