Reply to thread

Message: <blockquote data-quote="shovel" data-source="post: 1545086" data-attributes="member: 29855">remember that the fuel pressure regulator's job is to maintain fuel pressure across the injector not relative to atmospheric.   if the pressure inside the intake manifold is 0.3bar that's about 4psi absolute  which means fuel pressure relative to atmosphere would be about 30psi but fuel pressure across the injector is 40psi.  Fuel delivery rate changes very little with just <5psi in either direction,  without looking it up I believe fuel pressure at sea level with the vac. hose disconnected should be 43psi which is 3bar.   If that amount is correct then the amount with the vac hose will vary with vacuum and measuring it is of little use,  except if you end up with much less psi under load/WOT (clogged filter or failing pump or damaged fuel hose limiting delivery rate) because manifold vacuum should be minimum at WOT.</blockquote>