If you have an original pump I'm suprised the car works! If you have a small square looking pump it is probably a "Facet" pump. They are electrical low pressure (5-7 lbs.). You can buy a pressure regulator to lower/increase the pressure.
However I don't know that the pressure is the place to start. First clean the carb out good with carb cleaner. Maybe even clean out the bowl (rust and varnish sit at the bottom of the bowl), check the needle and seat, adjust the floats, check that the accel diaphram isn't leaking. Did the car ever run right? It may have the wrong jets. Also what distributor does it have? If it is the stock one make sure the vacuum lines are hooked up right.
The DFAV series 32/36 isn't as bad as people think, but it was originally designed for Pintos and Capri's. It crossed over as a cheap FI to carb conversion for a number of imported cars. Buy the Haynes manual on Weber carbs, it tells you how to adjust, rebuild and trouble shoot Weber and Stromburg carbs. I think it is part of their "techbook" series, I found mine at Pep-Boys (Shhhhhhh, don't tell Wayne) but Pelican sells the 914 and 911 manuals so check if PP can get the book for you.