You should see a noticeable difference on a drive. I would close off the fuel return to see what pressure is present. Should be quite a reserve or you should further troubleshoot the overall supply system. If basically no differance is observed while driving pressure may be sagging under load.

Basically at cruise under load fuel pressure may drop off too much Also a great way to see when filters need attention after a baseline is established. A healthy full pressure fuel supply system should also be a more reliable system.


I have noticed Roy has not posted in awhile as someone else mentioned. Hope all is well with him.