I got a recording going of the whole setup right now, hoping to catch the voltmeter when the flameout happens or when it doesn't ignite. Voltmeter is permanently hooked up right now to the gas valve and right in front of camera.Originally posted by rx7_turbo2
Unless you have a manometer(edit* day late dollar short)I wouldn't. You may end up just complicating any future troubleshooting.
Maxt mentioned earlier you have to find out if the gas valve is getting 24v and remaining closed, or does a loss of supply voltage cause the gas valve to close? This will help eliminate/confirm the gas valve as the issue. The fact you described the loss of flame as "abrupt" suggests there's a fault somewhere else that causes the gas valve to close.