LOL I would guess a Cosworth given the threads location.

By you saying you can't hear the pump makes me think you have a electrical problem, power etc? (Assuming the second pump was known to be good)

The servo assistance is achived by means of an electronic pump which you should hear run when the ignition is in position one, they don't have a conventional servo!

It makes no difference whether the car is on the ground or not.

Martin