98z with brand new 6.2 LS3. Engine started up and ran after about three or four revolutions when new. I drove the car about 200 miles to break it in before I was going to get a tune on it. Got busy with other projects for last 6 months and didn't get to it as soon as I wanted to. Started it up at least every week just to let it run to warm up a bit. Drove it a couple of weeks ago. Now it won't start. I have a pressure gauge on the fuel rail and I am getting 45 to 50 lbs of pressure but it slowly bleeds off over about 15 minutes. What could have happened just sitting? Is there a pressure regulator somewhere that might not be working right?

 

Externally charge battery overnight.
Then try to start the next AM.

 

Everett, I keep a charger on the batteries (one in rear) all the time. I have checked the voltage at the pump and I am getting 12.2 volts at the pump with out it running. I am starting to think it is the pressure regulator that is in the tank.