LT1 Starting Problem

[rabbitdog]

My 95 has an intermittent problem. It will crank fine, just not start. Fuel pressure is okay (about 45 psi) and I have a spark. Put a new coil in just for fun, still didn’t start. As it cranks it occasionally tries to start. After I crank repeatedly and for a very very long time, it will start, run rough for about 30 seconds and then run fine. Everything will be fine for about 3 months. Then it doesn’t start again. And I go through the same routine. Acts like my cars that had carburetors did when they were flooded. Any ideas?

One added symptom. Before it doesn’t start at all, it seams to progressively take a little longer to start each time. Not so much that it’s a problem, but each time I start it, it will take maybe an extra second to start. And the bang, it doesn’t start at all.

[wrightz28]

Does the fuel pressure drop off right away after you perform a running test?

[rabbitdog]

I've only checked the fuel pressure when it wasn't running. It seams to hold fine, but I guess I really can't say how long I waited to see if it dropped off. I'll try it again and gather more information. Once I get the thing started, it runs and starts fine for about a month or two, so I lose interest in trouble shooting it, thinking I won't find anything if it's starting okay. But I'll do the test anyway, what should I look for on a running test?

[wrightz28]

What I was getting at was if it holds perssure, doesn't necessarily have to be running test, but after the system is pressurized if it falls off quickly, ie- leaking injectors or faulty regulator.

Yours sounds more in the ignition control system at this point.

[rabbitdog]

Okay, here’s the pressure drop data. Key on to pressurize system. Key off. Pressure 43 psi. Then at 2 minutes, 42. At 4 min. 40. At 6 min. 39. At 8 min. 38. At 10 min. 37. At 12 min. 35. At 15 min. 35. At 20 min. 30. At 30 min. 26. At 40 min. 24. At 50 min. 21. At 60 min. 20. At 90 min. still 20.

Is this normal?