I probably should have put this in the TBI section - Moderators can move it:

Help!
383 w/ Holley TBI
16147060

Motor has been running a bit rich but otherwise fine and has started right up and run well even cold (first thing in the morning). For the past week it has been running richer after cold starts to where is stumbles a bit until closed loop kicks in (WB around 9.5:1 - 10:1). After closed loop kicks in it is fine.
Yesterday morning I attempted to start the motor and it fired then quickly died with a cloud of smoke out the tail pipe. Eventually I got it fired and was able to feather the throttle long enough to keep it running.
After work yesterday, same thing. I could not start it as it was totaly flooded. I looked under the throttle blades and gas was pooled in the intake pluenum. I unplugged the injectors and it started and burned off the gas, then I was able to again feather the throttle and keep it running long enough to get to closed loop (where it ran fine).
The injectors do not seem to be leaking but obviously something is wrong. I have a spare ECCM and tried that this morning with the same bad result. The chip I am using has been good for months but I did try another.
Once warm I can shut it down and it fires up no problem.

Any guidance?

 

What's your coolant sensor 'telling' the ECM at "cold" start? What's the Fuel pressure? Not in Limp Home Mode? Map sensor readings?

I'd suspect something mechanical, since "tunes" rarely "go bad".

 

Update: I got home from work today (did not drive this vehicle) and reviewed the 30 seconds of data-logging I was able to get this morning when I started it. The coolant tems was at around 3 degrees F. It showed 74 degrees after this afternoon and started up just fine. Seems to be intermitent but I will keep an eye on it.
Just in case it comes back I burned a CTS-fail-safe chip to cary around with me. I brought the cold temp Crank Air Fuel ratio vs Coolant temp up to 6:1 on all colder readings. Hopefully this could bail me out if it happens again.