I have an AU3 Falcon Sedan on factory LPG, and I have noticed recently that the fuel gauge will not go below three quarter fill when using the car. I use the trip meter as a guide as to how much fuel I have left in the tanks, but I would like to have the gauge working as well.

Would be a faulty gauge/dash cluster (easy fix), or would it be a faulty sender? If it is a faulty send in the tank, what sort of dollars would I be looking at to get it fixed?

Any help would be greatly appreciated

never heard of a faulty cluster... id be guessing the sender

I would say sender on LPG tank. I had same problem on EL it used to stick sometimes. PM GASMAN he sometimes has some senders. Not that expensive either i think $30 -$40 for a new good one or $20 for a cheapie. 5 minute job to install too. I know how annoying it was working from distance travelled. It used to * me right off.