I had started loosing prime to the CP3 a few weeks ago, having to prime it manually before it would start. There were times down the highway where it would set P1093 and limp, and when cleared, it would instantly pop back up for about 5 minutes, it also seemed a little low on power. My idle CFR bounces from 2-5mm3 at idle sometimes, and causes a rough idle. desired rail pressure is 4.7 and actual flickers .1 off sometimes, however at WOT I can sometimes be 4k under desired, coming in at 19k and slowly building to full rail pressure.. Balance rates aren't awesome, but are within spec, worst being -2.8. I had already rebuilt the filter housing once, I figured that maybe it was failing again and drawing air, so I installed a Fass 150 Titanium on it. I am still loosing prime, and now it gets airlocked to the point of me having to crack the bleeder screw, but I haven't ran it long enough to guarantee that all the air is out. There are no visible fuel leaks, and idle is still surging sometimes when warm, and rail pressure still lags behind desired for a few seconds at WOT. I also noticed it smokes a little more when I step on it at idle, possibly due to the fass. These seem to be symptoms of a FPR to me, possibly the PRV on the rail. Tonight I will be doing a bottle test and possibly an injector return test to narrow down my problem, but will a failing CP3 still reach full rail pressure? Or is this just the FPR?
