It was thought that this piece here, in the stock fuel pump assembly was a fuel pressure regulator.


Building a rock solid fuel system, this was going to cause me problems playing with the pressure, so I removed it, and had made a plug


My return line I installed on the driverside float assembly, because it was the easiest (the passengerside with the fuel pump, is all glued together)
Here is the return on the driverside


The 350Z fuel tank as 2 sides, with a baffle inbetween.

What was happening to me, was I was pulling gas from the passengerside, and dumping it into the driveside.
Checked both sides, and one was empty the other was full.

So I removed the return that was on the driverside, and put it on the passengerside fuel assembly
Got to looking at the piece, and noticed I could make a hole on the top, on one part, that would not effect taking it apart.
Here are pictures before I put in the return (didn't take any after)



It appears the thing we thought was a fpr, is not, that is just a valve that is used, to draw fuel from the driveside, once the pressure in the tank reaches a certain level.
So I removed the plug, put back the valve, and all seems to be normal.

I meantion this to the shop I was at yesterday (how I empty one side of the tank) and he noted that the SAME exact thing Evo owners went through. I guess they have the same gas tank layout.

Thought I would pass this along, for those that were following me, and wanted to get a plug.....

 

Say what? Are you serious??? I dont have access to my shop manual since I am homeless, but can you double check the shop manual diagram? If that is not the FPR, then where is the FPR?? Is there an FPR?? There is something that looks like an FPR just before the fuel rail which we know is a dampner....whatever that means.

How confusing.

 

I believe ACP found what he thought was ANOTHER FPR, but in reality, it wasn't. Just a valve.

 

The FPR is actually glue into the assembly. I don't think you can get to it with out tearing the thing apart.

 

so its pointless...I guess we just leave it alone....unless someone has another idea. Just overpower the darn thing with the Walbro 255 and use the Aeromotive FPR to establish pressure??

 

GQ,
Welcome to NC, how do you like the humidity/heat? I couldn't raise pressure or even maintain pressure under boost with that "valve" in place. I do have a 255 and SARD type R FPR so I know the proper hardware was there. Now with the mysterious valve plugged my pressure is a perfect 1:1 ratio w/boost. Maybe it has something to do with ACPs return being located on the drivers side? I really dont know much about this at this point if that wasn't the stock FPR that I plugged.

 

mprowe, thanks for the warm welcome! Someone should have warned me its FREAKEN hot in this place. It's been like 95 and 90%humidity. I night, you can drink the air...no kidding.

Are you in Charlotte to?

I'm not sure what to make of that FPR plug thing. A couple people have plugged it with success, so maybe it did have something to do with the fact that ACP put the return on the driver side.....strange..it is...

 

GQ,
Strange it is. Best of luck to ACP in getting this solved. You can just about drink the air around here from may thru sept.

MIKE

 

Miike I just PM'ed you...

You may be on to something about the side you chose to tap. The thing that concerns me is that some people have had success while others haven't, regardless of the side.

How many miles have you put on your car with the plugged valve/fpr?

 

Thanks for the update ACP. Back to the drawing board.

 

No problems with my Walbro 190L, just did a direct swap.

 

Yes, could very possible be just that.
Possibly running the return on the driverside messed with the tank pressure.
But all is good now, so I am leaving it till I have a problem...

 

Wait a second ACP, you kept the old valve/fpr as normal and you are able to increase 1:1? I'm sure I am missing something here?

Did you make any other changes to your system after you ran out of gas when you plugged the vlave/fpr initially? It sounds like you moved the line to the passenger side like Mike did in the first place. Its interesting how you don't have any more porblems now. I guess we should all tap into the passenger side?

 

Not only did I tap the passenger side but the rubber hose drains into the plastic pump assembly(where the thought to be fpr drained) and not into the tank. Not sure if that has something to do with it. I have drove over a hundered miles now and the gas needle is going down accordingly as well. Not saying that I am home free but the car is running strong and building great fuel pressure. Just wait for another hundred miles and I should know better by then.
MIKE

 

hey tim glad to hear you got it figured out, sorry i wasn't able to swing down, i am trying to get vortech to lend me a hand.... got big plans with a big blower...

ryan

 

Any updates Mike or ACP?

 

Mine is running fine, with steady pressure, so I have no plans on changing anything...

 

Whosdady,
So far so good and I still have the valve/regulator or whatever it might be plugged. Pressure is solid and car loves it! I wonder if ACP has his plugged or if he has the valve/reg in place? I should have some more confident results soon after more miles are driven and feel better about it. The car doesn't really move due to my work schedule so getting some results are slow.
MIKE

 

Thanks for the updates guys...

 

Still running good. I have drove well over one hundred miles just on the highway and near that same amount in the city. The gas needle and gas mileage match what is being used. This is with the stock fpr plugged and the return line on the passenger side.
MIKE