One day the car abruptly cut off while driving for no apparent reason, but it restarted ok, and drove symptom-free for a couple weeks. Then the other day it cut off about 2 minutes after it started, and then would not re-start.

I've turned it over for a few seconds with the fuel pump unplugged to de-flood, replaced the plugs, but still no start. It seems to be getting gas and I even tried plugging the fuel pump into a separate battery.

Plugging an old plug into each of the wires while cranking, there is a visible spark on both leading wires, but neither trailing wire.

When the key is turned to the start position and cranking the engine over, the only idiot lights that light up are the brake and seat belt.

What likely caused this and what to check next?

It's a mostly stock S3 GSLSE.

 

Trailing ignitor is likely dead. It works that way on the 12A models; no trailing spark = no fuel pump.

 

Thanks I have some other igniters laying around and will try swapping one with the trailing. Are the igniters the same for 12A and 13B, S2 and S3?

 

Which one is the trailing? I can't find a diagram.

 

I guessed the igniter facing the right is the trailing, and the one facing the front of the car is the leading. After swapping it out, the trailing plugs started firing, and the car started right up. The idiot lights still do not light up when the key is turned, but apparently that doesn't make any difference and I wasn't even sure if they should have lit up. The car is running again which was the objective.

Thank you very much.