Does the vtec pulsate(engage and disengage) after the engagment point? Or basically a lack of power? Did you replace just the pressure switch or the whole solenoid. The whole solenoid has 3 bolt that hold it to the block and has a screen to trap debree. I had problems with mine and the vtec would not engage at all so i replaced the whole solenoid(which is fairly easy so don't go to the dealer) and everything works fine now.