Large white smoke plume after 2 week sit first gen taco

Howdy y’all,

I just had my 04 3.4l 160k taco in the shop doing the famous 4wd trans swap and it sat for about two weeks no start until the day came to install driveshaft and test run the truck. My trans mechanic calls me telling me the truck turns over but won’t start and he starts thinking the a340f I brought to swap may be bad but I tell him to keep trying. Eventually he gets it started but tells me there was a MASSIVE white cloud of smoke that reeked of gasoline coming from the exhaust. Immediately he shuts it off and tells me to come over and check it out. Sure enough i go to turn it on and it takes a minute and eventually it starts and more white smoke. At this point it isn’t as white and more translucent but still visible and nothing I’d ever seen happen before. We leave it running and it dissipates after about 5-10 mins but it still smells like gas. Ive got the truck home now but now anytime i go to turn it on it’s a rough start and takes way longer than it used to. She’s always had a great start usually immediate and no hesitations and no roughness. What could it be??? I do have the CEL light on and it giving me a P0172. But still im so confused as to how it could have gotten to this when before having it at the shop it never had any issues. What do yall recommend/think?

 

Fuel is building up in the cylinders as you crank it for that long resulting in the plume of smoke and white cloud. The question is why is it taking that long to start. What happens if you give it about 20% throttle and try to start?