1991 MK1 Cabi Won't Start

Hi everyone so I own a 1991 MK1 VW Cabi and it has been sitting for the past four months over the winter in the garage not started. As it's starting to warm up a bit I decided to start it up to prepare it's for the spring/summer season. The car was working perfectly fine before it was parked. The battery was dead even though it was unhooked before it was parked so we jump started the car and it ran for about 20 min before she died. We assumed that it was due to lack of gasoline as she didn't have much in her when she was parked. We have now filled her up and charged her battery fully but she doesn't want to start any more. She cranks and you can tell she wants to start but just wont. Any suggestions on why?

Which type of fuel system do you have, Digi1, digi2, carbed?  Have you checked the fuel pressure, and Vacuum lines, is it in time?…..
 

Never a good idea to leave a metal fuel empty when the car is parked up over the winter as rust will form in the fuel tank if the car is left in a garage unless you have a nice heated garage or car cocoon.
If the tank is full of petrol there is less exposed metal to rust.

Could be you have a fuel blockage if you did run it dry?

As Briano1234 said helpful if we know what fuel system you have as that makes alot of difference what you need to look at do next….