FPR Before or After Injectors

[Animal15]

Car : AE86 , 16v 4AG with Adaptronic Base Map

Hi every one,
I got Sard FPR in fresh rebuild today I start the car for first time if I put it after the injectors like they said in diagram car won’t run properly; fuel pressure goes up and down

But when I hooked it up before injectors its run without any problem… but pressure gauge in FPR won't display anything, gauge in end of fuel rail display around 38psi.

(from day one when I show that diagram to my engine builder he didn’t agree with me he told me I should run it before injectors ; because I told him he put it after injectors and now he laugh at me )

But When I did research 90% of ppl says put it after injectors……….. Now I’m confused

cause i wanna do breaking before take it to tune so don't wanna run too lean or rich.

So would like to know anyone face this problem

[MWP]

Tank -> Fuel Pump -> Fuel Rail -> FPR -> Retun Line -> Tank

Fuel Pressure should go up and down depending on inlet manifold pressure.

[TERRA Operative]

I have a Sard on my 4AGZE and I hooked it after the injectors as per the stock setup and it works fine.

You got a genuine Sard fpr? There are a lot of fakes floating around.....

[trdee]

Your mechanic is doing it wrongs.

A fuel pressure regulator regulates pressure upstream by bleeding off excess fuel through it until the pressure meets the set point. This means the controlled pressure must be BEFORE the FPR, which means you need the FPR to be at the end of the rail. Unless you have a returnless rail, which you dont..

The pressure regulator is designed to maintain this pressure at a constant differential above manifold pressure, not absolute pressure. Example if you have 1 bar boost, you will see the rail pressure as the set point PLUS 1 bar, which is why you may be seeing the rail pressure change.

[RT40Corona4AGTE]

+1 for install the FPR after the injectors, the way they are designed it simply wont work before them.

I assume you tried adjusting it when you had it after the injectors? the way it should be installed.

Also, +1 for a lot of fakes around, I hope you didnt get unlucky and get one!

[Animal15]

FPR is not fake (got directly from japan through Jesse Streeter with fuel pump kit),

i know what u guys saying...

But what i can't understand then why it runs shity after injectors and quite good before them

[1gjet]

Could just be wrong fuel pressure, could be not enough for your injectors or could be too much.

[trdee]

you sure you havent routed your lines some retarded way and it actually is after the injectors when you think it's before them? look at the flow path carefully.

if not, then something else is dodgy with the tune etc. it simply should not work the other way, unless you went back in time and killed isaac newton and made yourself the god of physics

[RA35GT]

What base pressure was used in the adaptronic map? and what base pressure is set on the fpr
Are you also using the same size injectors? (or entered the injector size into the tune appropriately)

[Animal15]

trdee

i follow this


as Tune
base map install by Status (for 210cc that what i have ), don't knw abt map pressure
so how to know FPR pressure with out hooking up...

[jondee86]

You have to take the OEM (factory) fuel pressure regulator off the rail, and use
an adaptor to give you a hose tail that you can use to hook up your Sard. It's no
good hooking the Sard to the tail off the OEM FPR. Then you have two regulators
in series, and that ain't gonna work !!

Cheers... jondee86

[Animal15]

yeah i remove the OEM FPR only got OEM Damper

[RT40Corona4AGTE]

umm yep, having the stock OEM one still fitted is bad thing and could cause the problem you are experiencing. But i doubt you would of left it fitted, it pays to mention it though.

Can you take a photo of your setup for us perhaps? that would be so much easier? also check that you havent got your feed and return fuel lines mixed up by accident?

[Animal15]

here....

but i remove the FPR as you can see filter ---> Rail




this what i got in my phone right now... 2moro when i visit da workshop get one with FPR fitted.

[TERRA Operative]

I think you have yours a bit mixed up?

It might not make much difference, but on my GZE, the inlet (with the damper) is on the gearbox end of the rail, and the outlet with the adapter going to the Sard is on the cam belt end.