86 GMC - won't start unless gas poured in carb

[kcackler]

So this truck was starting and running just fine a couple of weeks ago. We let it sit for about 2 weeks, and I went to go start it today and it just would not start no matter what I did. So I put a little bit of gas into the carb and she fired right up and ran for a few seconds before dying. Tried starting again, and the same thing...It just won't start unless I put gas in there, and when I do, it won't stay running.

What could have happened in two weeks that could be causing this, and what do I need to do to start troubleshooting? We've GOT to move this truck in two weeks, and I'd like to be able to drive it to its new location instead of towing it. My first thoughts are maybe a clogged fuel line somewhere, or maybe the fuel pump crapped out while it was sitting?

Any tips or advice will be very helpful. I'm a bit green when it comes to carbs, so please walk me through whatever troubleshooting needs to be done. I'm willing to learn, just need some help along the way

Thank you!