My 1989 5.0 recently started turning over for about 5 seconds before it actually starts. it has new plugs, rotor and cap. I thought it was a fuel issue so i replaced the injectors, runs better but still wont start right away. My fuel pressure gauge sits at between 30 and 40 psi at all times. It has an aftermarket fuel pump which turns on and off manually. My frined seems to think i have some rings going out and that this is the cause.. Any input?