You have a fuel pressure problem here's how to test it:
Fuel pressure test:
This determines if the fuel pump is capable of building adequate pressure to satisfy the fuel pressure regulator. It will also determine if the system is able to hold the fuel pressure. If the pressure is insufficient, or the pressure does not hold, this test does not determine what the problem is. It only confirms that a problem exists. Fuel pressure must be tested only when the engine is cold. This avoids increases in pressure by heat radiating from the engine causing erroneous readings. GM does not publish engine running fuel pressure specifications in the “dealer issue” shop manual. Make sure the fuel filter is not clogged with dirt before testing fuel pressure, easiest and best just to replace it. Here is a link to an adequate, inexpensive, fuel pressure tester:
http://www.harborfreight.com/cpi/cta...emnumber=92699 Install the fuel pressure gauge to the test port near the distributor. Turn the key to the RUN position but do not start the engine. While the fuel pump is running, fuel pressure must be 60-66psi. After 2 to 3 seconds, the fuel pump will shut off and the fuel pressure must remain above 55psi for 3 to 5 minutes. A drop in pressure below 55psi indicates excessive leak down.