Hello. My 760 B230 FT appears to have a monthly cycle. It's driving me nuts!

I've kept the thing in good running shape, lots of maintenence, new parts etc.
About once a month though, it seems to just die out for no reason for about a day. Then it gets back to normal, and runs great, lots of power, decent gas mileage, smooth idle and all the rest. I replaced the Temp sensor (ect), cleaned the IAC according to the FAQ, have gone over the wiring looking for shorts, taped up or shrink -tubed any naked wires, pulled the injectors looking for leaking ones, replaced the O-rings, yadayadayada.
When it decides to bitch out on me , I can smell gas like crazy, so I assume its flooding. Now is it because there's insufficent spark? (bad coil?) or is it because one of the sensors decides it feels like giving the pistons a gas-bath?
Right now, there's no easy answer!!!!
I re -shaved the head 6 months ago ,new head gasket, intake -exhaust gaskets, water pump, t-belt tensioner, and plenty of love in other areas....

It has 300,000 kms. on it, doesnt burn any oil, and 29 days a month this car seems like a real keeper. Except for that one day!!!!!

could there be some wierd time -circuit in the ecu? I know that's streching the imagination, but I'm at the end of my wits here. I have read of simalar problems in other posts, but they don't match up with my personal grief.

ANY comments would be appreciated!!

Josh 86 760 B230FT
Regina Sask., Canada