1981 turbo spider will not stay running

[russcase1]

I drove this car 100 miles witch is unusual for me since we only drive it around a golf course community in the summertime. The car always ran great and has only 34,000 miles. When we came home we parked it in the garage as usual. The next day the car would start but would not stay running even featuring the gas. Reading the forum and bringing a mechanic to the house we changed the fuel filter, throttle control valve, fuel pressure regulator,coolant sensor, and mass air flow sensor and the car is the same. The car runs if you disconnect the mass air sensor. Spent over 600.00. What is the problem!

[focodave]

I had the exact same problem on my 1980.
The problem is related to the dual relay set -- or something connected to the dual relay set.
I had the exact same symptoms.
I would disconnect the air flow sensor and the car would run (it ran rich, but it ran).
With the air flow sensor connected, the fuel pump would run with the ignition in the "start" position.
As soon as the engine fired and the ignition key was returned to the "on" position, the fuel pump would stop running.
Disconnect the air flow meter, and the fuel pump ran fine.
I removed my dual relay set and I ohmed out the pins. I found an open circuit.
I bought a new dual relay set, installed it, and the car ran perfecty for about 10 minutes.
I shut the car off.
Then when I started it up again, I had the same problem as before.
I "fixed" the problem by installing a fuel pump toggle switch that turns the fuel pump on "hard".
I know it's not the safest thing in the world because if I were ever in an accident, the fuel pump may continue to run if I forgot to shut it off in all of the potential hysteria that occurs when there is an accident.
But at least, now, the car runs great and I will one day, (hopefully), figure out what the heck is blowing my dual relay set.
I'm an electrical engineer, by degree, and even I am stumped by this problem right now.