P0093 Set after line replacement, and service

snw blue by you · October 29, 2018

Owner's personal rig. 2015 F450 Platinum 4X4. Tech performed a service after replacing a fractured fuel supply line from the HPFP to the LS rail. It is the line on the RS of the pump standing in front of the truck. History has revealed that this line has been replaced a total of 3 times so far. All isolators are present, so vibration does not appear to be the issue. Anyways, filters have been replaced but now the truck will not pass the high pressure test, fails at 2nd step, and sets P0093, and P0087. Additionally note that the secondary filter is extremely noisy at KOEO. PPT M for P0093 has not revealed any obvious issues, and unfortunately the tech disposed of the filters so visual inspection is out of the question. PCV, VCV, and FRP sensor all replaced to no avail, and with varying results. The owner asked me to step in, and additionally have another tech continue diag. I have placed a more senior tech on the concern yet we are not making any progress. Base FP is at 70 psi at all times, and the LP pump/filter housing has been replaced due to what appeared to be a crack inside. It has now been years since I have wrenched, and my time to help is limited due to management responsibilities, so any help is greatly appreciated.

Keith Browning · October 30, 2018

These are the wierd ones you don't see to often, which I personally have not so I have nothing to give sadly. Please do let us know when you crack this one. For me, the off the wall one's with no obvious or diagnoseable cause seem to always end up being a HPFP. Good luck!

Question though, the fractured fuel line is one of the steel lines right? I would think that there would have to be some serious stress (excluding vibration) to do that like pressure spikes that it's not designed to withstand. (thinking out loud here)

Hot-Line has nothing for ya? Self help on the Hot-Line form?

cbriggs · November 9, 2018

Any time I've had a noisy secondary fuel filter its due to air ingestion on the suction side. Have seen a few cracked sending units cause it. Could it be possible that the hp pump is slightly loose and the movement is fracturing that line?