Here's what I found on Carter's website regarding this type of fuel pump:
http://www.carterfueldelivery.com/fuelpumps/electric.php
Solenoid designs:
Solenoid pumps, the most widely used universal type, are designed to fit many universal applications. They’re available in many different pressure ranges and for use in 12-volt, 24-volt and, soon, 6-volt applications. Solenoid pumps allow fuel to flow through the pump even when the pump is not energized. Rather than a motor, the solenoid pump uses a piston actuated by an electromagnetic coil to generate fuel pressure and flow. By using only short pulses of electricity, the solenoid pump is very energy-efficient. It is also long-lasting, with no internal rubber parts or bellows to wear out.
Remember: To ensure long life and keep your warranty intact, be sure to install a new fuel filter on the inlet side of your universal pump!
I guess it's not a diaphram type, but a piston type. I'm going to perform an autopsy on the old pump, so whenever I get to it, I'll report my findings.
Here's a 'mug shot' of the guilty party.
Michael
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.