Engine Bogs, but not a fuel pressure issue?
 

I've got quite the challenging problem.
2013 Scion FRS; NA tuned and in process of setting up Flex Fuel.

I was going through some tuning revisions with Zach from CSG and needed to fill up to a full tank of gas. After filling up, I got on the highway and did a pull for datalogging successfully with no anomalies. Shortly after completing the pull, no more than 5 minutes. The car outright dies. After pulling over and checking for anything catastrophic like a window in the block. I tried starting the car. Never kicked over, just kept spinning the engine. Zach later confirmed no issues with the tune, everything looked fine. After towing the car home a few hours later, I was able to start the car in my garage with 0 tricks/gimmicks. However upon starting, the car bogged and immediately dies. I datalogged the event, and it shows .4MPa at the fuel rail reducing to .1MPa when the car dies. So that tells me the fuel pressure sensor is reading fuel; and that there isn't enough getting to the rail as it should be 4Mpa for idle.

Before I did anything, I swapped my Walbro basket from when I was boosted; to an OEM one. I had the basket on hand and figured it could be an easy fix/swap. Hoping that would clear up the issues. No luck. Same issue. So after taking some measurements right before the HPFP; I verified 58psi - .4MPa was coming from the basket and into the HPFP.

I just installed a junkyard HPFP hoping that would clear up the issues but no luck again. Same exact issue. Car starts right up and immediately bogs out due to no fuel. Upon reading the codes, I only get an EVAP code P0451. I don't believe that should be creating the issue I'm seeing but maybe I'm wrong. When I was boosted, I had hard pinned the EVAP hoses underneath the manifold so I will double check with a boroscope and see if any popped off. Since the issue is HP/Basket fuel pump agnostic, I have a hard time trying to figure out where to look next. If the fuel rail pressure sensor was bad, I should have more codes.

Any suggestions or ideas?

check the MAF

MAF is reading fine. I recorded the event with my datalogger today after checking all evap and vacuum lines. Below is a screenshot of the fuel pressure to engine RPM which shows virutally no pressure is being built by the HPFP. However I replaced both fuel pumps and had no issues turning the engine and verified the rocker moved accordingly. I should be getting 4Mpa but I'm getting fuel basket pressure at the rail sensor...

The only thing I can think of is that there is something wrong with the DI Fuel line where its getting pressure but not able to flow as much as it should be able to.

https://i.imgur.com/Rqe6yA9.png

I went ahead and bought fuel hose and routed off the basket to the engine lines directly just to see if the lines were possibly blocking or limiting fuel into the DI system. Nope. Didn't fix it. Looks like I'm going to be taking the manifold off of the car and seeing if I can find anything in the hard lines.

Bubba says you got some "bad gas".

:iono: