car suddenly quits...fuel or ign?

[Sixpactogo]

I had the same issue when I upgraded my car to the orange box. My problem had me baffled for a while with the same exact intermittent shut down.
My problem was a grounding issue with the orange box. I tried the coil replacement because it seemed too hot. Kept throwing new parts at it until I realized the orange box was not getting a good enough ground through the mounting screws. If it does not have a good ground, the circuitry in the box will get hot and open up. The circuit closes back up when it cools down.
When it shuts down on you, put your hand on the orange box. I bet it will be too hot to touch. People think the ECU failed but more than likely is the ground. Check it with an ohm meter. Should not read more than 3 or 4 ohms. between the box and battery neg.

 

[tommytmopar]

I had an ecu do that to me. Intermittent until one day it died completely. Voltage at coil should be about 7 to 8 volts. When you crank voltage will go up about 2 volts then return back to 7 or 8 after ignition. Do you have the 4 prong ballast? If so one resistor is 5 ohms and one resistor is 1.2 ohms. You want to be running on the 1.2 ohm. The 5 ohm is a protection ckt. For when they had 5 pin ecu. If the resistor gets reversed you only get 3 to 5 volts at your coil.

 

[Bruzilla]

If the engine starts to start and dies immediately as soon as the key is released, it's a bad ballast. What it sounds like is happening is you have contact somewhere when the engine is cool, then as things get hot, and your connection starts expanding, the connection is lost. This could be happening within the ballast.