Chevrolet Repair: TBI Fuel Injection, intake manifold gasket, gasket intake

Question
I have a 1988 S-10 Blazer 2.8 Liter Engine with TBI Fuel injection. My problem is when I start the Blazer it will idle for about 2 or 3 minutes. When I try to give it gas it dies out.It will die out hot or cold.When it runs for the 2 or 3 minutes it won't restart after it dies out. I've replaced the throttle body, throttle body gasket, intake manifold gasket, and the fuel pressure seems to be okay. on start up the Vacuum is around 12psi but drops off as it runs. as the idle drops off too. I don't know what else to check. Can you help me out with some suggestions or ideas.?

Answer
Hi David,
That vacuum dropping sounds like the exhaust system may be plugged. Can you pull it apart in front of the converter to test it?

Make sure the EGR valve isn't opening...that will drop the vacuum reading bad.

You say it dies hot or cold.  How can you get it hot in 2-3 minutes?
The plugged exhaust would make it heat up pretty quickly also.

Your 2-3 minutes, and then no start, is because it goes into closed loop, and then the ECM controls stuff, and probably doesn't like something.
You could try unplugging the Temp sensor...not the gauge sender, and that might let you start after it heats up, but won't fix the problem.

As for the fuel pressure, it needs to be at 12 PSI while running. Find a way to test it...either "T" in a gauge, or borrow a tester. Many parts houses will loan one if you buy needed parts from them.

Van