Ruddager

I bought a 1990 100 from a kid for 200$. He said that it wouldn't run, but after putting jumper cables on it, it started right up. Absolutely no hesitation. Then after about 5 minutes of idling, it just quit. Then it wouldn't start at all.
I took the battery to my house to charge, and came back to get it with a truck and trailer. With a charged battery it took a few tries, but finally started, and once again after 5-10 minutes it just quit, and did not show any desire to start again.
I have no idea what's wrong. I'm assuming fuel pump, or intake problem, or distributer problem, or some sort of a sensor... I just need some help.

audiqv8

First off you will have more response if you post on the 100/200/5000/V8 forum.
I would remove the fuel pump relay and use a jumper to get the fuel pump running, could be just a bad relay. If the problem still persist then I would check fuel pump.