If it drove one day and not the next...
Switch the DME/Fuel pump relay with your spare.....No spare make a jumper:
DME Relay Information and Testing
Top Back of the engine where the reference sensors connect. Wiggle the 2 wires. Check for cracks in the insulation. Clean the contacts.
Tighten the big ground on top of the bell housing and clean the battery connections. Put a piece of tape over the bell housing TDC Hole to avoid droping a nut in the clutch.
Fuel filter----when was it last changed?
Here are further ideas
Bennington Motorsports
GL
John