Chevrolet Repair: Fuel Problem, upper intake manifold, sequential fuel injection

Question
Hi Robert. I am trying to determine what is wrong with my 1996 1/2 ton Chevy Suburban, 350 Vortec, 175000 Miles. It sat all last summer because it would not start. I pulled all the plugs and cleaned them and it started but didn't run well. I replaced all plugs and distributor cap and it ran great for about 6 weeks. Then it just died going down the highway. It will not start at all again. I have spark to the plugs but it seems slow to me. The ignition control module tested bad so I replaced it. The fuel pump was replaced 2 years ago. I put a pressure gauge on the test port 4 days ago and it is holding at 15lbs. It does not change when I crank it. I'm thinking pump or pressure regulator but neither of those are very attractive to change in the street.
Thanks.

Answer
If you now have good spark, the fuel system should be looked at next. If you have the Central Sequential Fuel Injection system identified by a black composite upper intake manifold, 15 psi fuel pressure is way too low. You need around 55 to 60 psi. Most likely you have a defective or leaking internally fuel pump. Don't rule out a clogged gas filter...check that too.