When i start her up, she runs for a few seconds then shuts right off. But if i keep a throttle to her she'll stay on. And as soon as i lay off the throttle it putts around and shuts off. I have to keep the throttle down for a little bit before i take it off, then she runs fine. What would cause this?
BTW, this is a 1996 5.0L Bronco
Oh and BTW, it didnt start to do this till it started to get cold out. When i drive it and park it for like an hour, it doesnt have that problem anymore. But if i let it sit over night, ill have that problem again.
I forgot to mention, its not an instant shut off. It rough idles and spits and sputters. Then shuts off.

 

Your truck should be OBDII, if you have access to a scanner it would help a lot.

Is your engine light on?

I would check to see what temp the computer thinks your engine is, and what temp it thinks the incoming air is.

Cold engines need more fuel to run, if your computer isn't seeing the correct temp it won't increase the fuel delivery and the engine will not run, or run poorly until it gets warm.

By giving it throttle you are giving it extra fuel and moving the air through faster which also helps keep it running.