Having some strange fuel delivery grimlins... fuel pump, filter, fuel pump driver all working perfectly. Fuel pressure regulator has been replaced, along with an injector upgrade to the 12 port 24# focus st injectors. At idle it's steady at 27-29 psi (seems rather low to me), and with no vac it jumps to around 40-43 steady at idle. (Seems legit). However when in running config. It jumps and bounces radically between 38 to 50 psi under throttle ramp. I know instability in this set up is normal hence the secondary dash pot on the passenger rail.... doesn't seem to be causing an issue at this point but definately down the road. Anyone seen this water-hammer effect before? Oh, pretty stock set up, ported cobra intake, modified imrcs, vacuum stays dead steady while fuel pressure hammeres around..