hey guys, 03 ap1 here, 76k. i've been tracing down a power loss problem for a few months now. it almost feels like i have about 400lbs in the trunk, some days are better than others, but it's not like it was when i first got it in april of this year.
i was fidgeting around today and the first thing i noticed was that the line from the intake to the pcv had an extra pcv in the line??? don't know why really, is this anything you guys have seen before?? regardless i've removed it and re-piped the hose. i tried to do the pcv inspection per helms manual, but couldn't get the pcv to make any sort of clicking noise by crimping the hose as described in the manual. i pulled it out, cleaned it, and still no clicky noise.
then i was fidgeting further and happened to pull the vac line off of the fuel pressure regulator. the car instantly perked up and seem to run even smoother than it already was. so i gave the throttle a quick snap and as it dropped back down into idle, i didn't get that stumble/ engine shake feeling that i was used to. so then with the vac line still disconnected from the fuel pressure regulator i went for a drive, and what do you know, i got my old car back. it seemed almost as peppy, if not as peppy as it did when i first got it.
i read through the manual a bit more and looked up some "how this works" videos on fuel pressure regulators, and it seems by disconnecting the vac from the fuel pressure regulator that i've increased fuel pressure a bit. from what i've read it could be a bad fuel pressure regulator, clogged return fuel line, clogged fuel filter or pump on it's way out. i haven't had any starting issues and the only code that pops up is a p1457 (evap leak), and it only comes up once a month or so.
so i'd like to diagnose this, but i need a way to test the fuel pressure. the helms manual has a gauge/adapter kit listed, but do you guys have any experience with the thread size at the test point(fuel pulsation damper?) i have plenty of gauges that can test liquid psi, but i'm not sure what adapter i'll need at the pulsation damper threads.
check this video out if you don't mind. it's basically a reiteration of what i just typed.
this was my original thread, it has descriptions of what i've done so far. pretty much everything but a fuel pressure test.