94 bravada wont start

good fuel preassure when turned on but leaks down to 30 psi when turned off but when running stays at 60 62 has good blue spark at all plugs dont under stand if when running pressure at spec why wont it start is pressure stays up when pump is on that every on says if there is aleak it would cause it not to start also would a code 43 causeiy not to start freind said be for it died it would loose power and not go any where untill he unhooked battery while it was running and hook back up then it would go and finaly it just died and wont restart

I see a post for a '99 and a post for a '94. Which one is it? They're different because of different fuel injection systems.

I see a post for a '99 and a post for a '94. Which one is it? They're different because of different fuel injection systems.i have two differant years of this vehical

You have excessive fuel pressure leakdown. Key on engine off pump running should be 60 to 66psi. After pump shuts off, pressure must remain above 55psi for 3 to 5 minutes. Could be a leaking check valve in the fuel pump, pressure regulator leaking, or the lines under the plenum leaking.

The code 43 on the '94 is likely the knock sensor just in front of the rear sparkplug on the drivers side. The connector gets real brittle and if brushed while changing the sparkplug next to it, it'll break apart. Give it a look.