its got a 2.8L - just bought it the other day

the first cold morning (roughly 20 above) it sat all night and got inside, cranked over and it didn't fire, I did this for a good 30 seconds on and off. let it sit, popped the hood and didn't see anything amiss, the battery is strong btw...so it cranked over pretty fast...I got back in and pumped the gas, and it started firing, got it to start...same thing happened this morning, just cranked over, let it sit for a minute or so and it fired...now it wont even after doing what worked....it just cranks over

I got some starter fluid and it would fire but wont stay running.

Side note: during the day, when we are running errands, turning on and off, wouldn't have any problems, started right up, ran fine, idles fine.