Legacy GT Cobb Flex-fuel install issue?

I just had the Cobb flex fuel setup put in and it wasn't without issues unfortunately and cost me a lot more than expected in labor time. At first I was a bit confused since my installer was saying it would take more time, but after walking me through the issue, I'm inclined to believe his take.

If you're familiar or comfortable with setting up your own fuel lines this probably isn't speaking to you, but for those of us who dabble when we can save money but have spent way too much on the car to wing it on fuel setup, this is for you.

Based on my installer/tuner, it looks like Cobb's official instructions for the FPR install is fubar'd and because the fuel lines are cut based on those instructions/images shown and because the FPR is oriented incorrectly, a few of the lines no longer fit and need to be custom made again.

For reference, look at the GR WRX STI fuel system instructions here:

https://cobbtuning.atlassian.net/wiki/spaces/PRS/pages/51839096/315200+-+COBB+Fuel+Pressure+Regulator+Kit

In step 4, it says that the FPR return line (curved port) faces the firewall. This FPR is used in the Legacy Kit.

However in our instructions, seen here:

https://cobbtuning.atlassian.net/wiki/spaces/PRS/pages/710869010/314200+-+Flex+Fuel+LGT+OBXT+05-09

In step 2, that same FPR return line (curved port) is facing the front of the car and they have the return lines hooked up wrong and according to my installer, the car should not start be able to start in this setup.

Has anyone installed a Cobb Flex Fuel Kit yet? Are you guys seeing the same thing here?

By the way, here's how my setup ended up looking.

Do you have the e-content sensor on the feed side or the return? It appears on the feed side from what im seeing in your pic but im on a phone so it may be the picture.

Dave

I want to say it belongs on the return side on that application. should go tank-fuel pressure sensor-feed to engine-return from engine-flex fuel sensor-fuel pressure regulator- tank.

Dave

any update?

Dave

Hey Dave,

Thanks for checking back. Cobb is adamant that their instructions are correct. See below.

My mechanic prove their response wrong by making these 2 videos to prove a point:

My question to you Dave (and anyone else familar), is do you set it up where the return side of the FPR has the feed line in?

This thread might be of use.

Looks like your mechanic got it right.

Appreciate the link, if my mechanic is right though then the fuel lines are not long enough for this "kit" to work out of the box right?

My whole complaint about this is the extra $ necessary to fabricate new lines that work given the new orientation of the FPR that my mechanic had to put in place. Their kit is priced for and advertised as PnP.

Anyway, if the kit stays as-is, I'm just hoping that people considering the Cobb FF kit understand the potential extra costs during install.

hmm, well I can say that I would think a simple fix would be to flip the regulator over and that should fix the length of the lines supplied to and from the fpr on the setup they list but may come in contact with something else. I cannot comment on running the return line into the lower port on the fpr and still seeing flow through the side port as I have always mounted them as it lists in the GR kit which would be fuel in from the side port and out through the bottom port on an OEM style fpr.....I would also agree it should obstruct flow trying to put pressure on the lower port/diaphram directly from the bottom but it comes down to *I've never tried it so I dont know lol*

The kit instructions for the LGT are shown using the process I mentioned which is mounting things very different than you did and having the flex sensor on the return side in between the engine and Fpr.

tank-fp sensor-engine-flex sensor-fpr- tank

Where as you installed it

tank-fp sensor-flex fuel sensor-engine-fpr-tank so I'm sure the lines for that type of setup are not going to work as intended...

I have not had a local kit installed yet but if I ran into this I would try to just mount the fpr upside down and use the current line or just extend a line a little since it can be used with standard fuel line as long as its high pressure.

I would submit your pictures to cobb and see what they say, it sounds like they are half right and possible half wrong...

Dave

Hi Dave! I’m curious if Cobb’s Flexfuel kit is to support an 08 Spec. B? Only issue I’ve seen is that my 08 Spec. B has a 5 pin TGV connector vs the 3 pin for the LGT’s.

Sent from my iPhone using Tapatalk