Is the inducer capacitor on the board ?
Originally posted by docholiday
No that furnace doesnt look for a solid flame signal for 7 or 8 seconds after the gas valve opens, if its shutting down in 2, odds are the pressure switch is opening. Its not a gas valve or limit switch. If there is a small window in the blower door, count the flashes and report back.
Now find out why.
Could be overfired, could be a venting issue. Could be a weak inducer or inducer capacitor. Im not so sure about moisture since it will recycle. Moisture in the PS line would hold the PS in one position or the other.