I know when I had these issues it was the switch. I temporarily put a drag racing switch panel and push button in the car and it ran great. In fact, even though I have a new switch, I left the drag panel in the car. It's fun hitting all the switches and push button starting.
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.