Did you sort this out?
When you say "die", does the car buck and shudder causing you to loose speed slowly as the engine fails? Or, does the engine stop "bang" and the car's nose lurches down to the pavement until you push in the clutch?
Fuel failures will be bucking, jerking, shaking stops. Ignition failures will be quick and complete unless it's an overworked ignition coil (or a weird condenser failure) .
You said the engine restarts while coasting with the clutch pushed in? Pedal down? That makes no sense as there is nothing causing the engine to want to turn over if the clutch is in and you haven't touched the ignition key.