If you were to disconnect the O2 sensor it would run open loop if it will run at all. You could try that to see if it will stay running long enough to get up to and stay at operating temp. I would bypass the heater before I ran that sealer thru it if it's made out of what I think it is.
You sure once it warms up that the AF leak isn't opening up to the point that it's hydraulic locking the engine, making it quit? Looked like a lot of green in one of those pictures you posted.
Kevin
It's not locking the cylinder because the motor will crank over easily, just won't fire. Should I disconnect the downstream 02 sensor? The pic is after it sat overnight.
