I have a 99 Accord V6 and it doesn't want to start when the temp drops below about 50°f. Fuel pump seems fine. Pumping gas pedal does not help, in fact I've found the best results by not touching the pedal at all and not cranking for a long time, rather given it a two-count and stop. Wait a few seconds and crank for a two-count and stop. When it does start it runs rough until warmed up, then it's fine. As long as I don't let it fly cool off it starts normally. If it does cool off problem returns. Not sure if there's already a thread going on this, but I didn't see one at first glance. Apologies if there is. I'm between jobs so need to get it going ASAP so I can keep up the job hunt. Thanks in advance!

 

First guess is to check / clean Idle Air Control Valve. I can see temps giving bad info and so it won't work when cold.

Hopefully this helps show you where it is and how to clean it.