Any one have any ideas on what to do my hpfp act pressure is instantly droping when I get into boost I have changed hpfp , internals , prv, and the filter sock and am pretty lost at this point!
You changed the pump with a known working pump from another vehicle? or did you replace the pump with a new unit?
When you replaced the internals, did you disassemble, inspect and clean the spill valve?
What tests have you performed? KOEO will show your tank pressure, 50-60psi.
How did you come to the conclusion the PRV needed replacing? Have you performed a PRV test? Like this one...
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I had old KMD hpfp internals and while flogging to get logs for tuner the pump just failed. Not in the normal sense, a complete drop in max pressure at high injector IDC. Drooping of pressure. So did a complete clean of hpfp, install of e85 o-ring kit and new auto tech internals. Problem went away.
Start from basics. Take hpfp apart completely, clean everything. Many threads here to show, and help. Search and read this forum hpfp threads.