1985 Cimmeron stalling and no power

I have a 1985 4 cyl Cimmeron, which has the same engine as Chevy Cavalier. This car I just took out of storage(10 + years) and had it running great. It only has 32k miles. After running great for about 100 miles all of a sudden it doesnt idle right and I have to keep the engine racing at 2000 rpm's else it stalls. When I try to drive it it has no power and I can hardly keep it above 5mph. No trouble codes come from the computer(just outputs code 12's).
Any ideas. How does the computer control the timing? I think it may be timing related, but I dont know.
Thanks

Got sufficient fuel pressure?

I don't know, but that sounds like a posibility. Any easy way to check that?

Got sufficient fuel pressure?

Thanks for putting me on the right track. I pulled the tank and noticed the fuel pump (in the tank) had a short 2" connecting hose with a split in the side. So even though the pump worked okay, fuel would squirt out of the hose all inside the tank. I'll let you know when i get it back together if it runs okay, but im pretty sure this is the problem

Also a tune-up wouldn't hurt