HPFP Pressure low after upgrade
Posted: June 4th, 2025, 5:34 pm
So I just had my HPFP apart to upgrade the internals and rebuild it by changing all o-rings, and at the same time I upgraded the intake to a corksport 3" power series. I updated the MAF calibration to the calibration info that corksport provides for this intake. the hpfp did give me a bit of a hassle with the spill valve being somewhat seized up, but soaking it in some seafoam for half hour allowed it to move inside of the threaded housing and i was able to push the center out and change the o ring and get everything back together. i was really careful with the whole valve, cleaning everything really well but also being damn sure everything went back together properly and correctly. screwed the spill valve back into the hpfp lightly, reinstalled the hpfp onto the engine, then poured a bit of seafoam into the spill valve and then snugged it back up very lightly. restarted and saw the hpfp presssure was super low (like under 100), went out and snugged the spill valve up a bit more and the pressure came back up to around 350 psi or so. but as the engine ran, the pressure came back down to a bit under 200. when i rev up the engine a little it does come up over 500, but it defintely does not come up NEARLY as high as the factory internals did (i upgraded the internals to the corksport interals kit). Now it doesn't go above about 800 psi!!!
please help! logs attached for a short drive, you can see the hpfp pressure does drop, and causes knock near the very end of this short drive once.
please help! logs attached for a short drive, you can see the hpfp pressure does drop, and causes knock near the very end of this short drive once.