Sounds like you could be boiling the fuel in the carb. When that happens you will get a very slow/hard crank or a almost no crank. Easy to see go out for a drive and when you get back use a infra red temp gun and see what the temp is top of the intake compared to the carb base and bowls.
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.