I have 96 blazer. It only starts when you turn the key to on 7 times running fuel pump each time. I checked fuel pressure under the hood at fuel line port it was only 48psi after 7 times turning the key to on then I started it the pressure went to 52psi. Then 55psi when I shut it off. And after ten minutes 49 psi. I read the fuel system diagonis on the forum but it doesn't say what low pressure means. I think a bad pump or filter but just replaced 3 years ago. Any help would be apperciated. Thanks steve

 

If it leaks down, you have a leak in the system. You could have a weak pump combined with a bad check valve in the pump. You can confirm this by testing fuel pressure at the feed into the filter next.