I got a 94 LT tahoe blazer. Brand new battery and full pump is almost a year old. When I get in to start it, it starts up like a champ but after about 15 minutes of running it just dies. When i try to start it back up, it just cranks but wont fully start. If i let it sit for about 45 minutes to an hour, it start right back up. Before i bought it had sat for a little over a month. I put HEET in the gas tank but still just died after 15 minutes. Any Ideas? Snow is coming soon and I got to park the Camaro

 

Test the fuel pressure & leak down. The fuel pressure port on the CPI engines can be interesting to access. It is located off the back side of the intake manifold between the distributor and the brake booster, closer to the brake booster.

I would bet that you have a leak inside the plenum. The CPI engine is notorious for fuel pressure regulator (FPR) failures which results in fuel dumping into the intake manifold. Too much will cause the engine to stall and not restart due to an overly rich fuel mixture making its way to the cylinders.