When you say "rebuilt"... what does this mean? I assume you put in new sleeves... did you take the kicker lever (piece that hits the ball) off of the fulcrum piece and clean?
I see four real places that can cause sluggishness... 1)sleeve/plunger wear 2)wrong solenoid, 3) gunk at the fulcrum, 4) kicker lever rubbing on saucer.