Sard 700cc Injectors At 95% Duty Cycle At Only 260awkw?

[candy33]

Hi guys i got an r32 GTR with a Garett t04z turbo, 60mm wastegate, 260 poncams and Vipec ECU.

And i got it tuned but there isnt enough fuel available, i could only get 260awkw at 13psi with the injectors maxing out.

I got a Sard 280ltr pump, Sard 700cc injectors and standard fuel rail and lines.

What could be the problem?

[N1GTR]

Is the fuel pump restricted in any way? Lines clear? Enough voltage to fuel pump? Fuel pump mounted correctly? Lots of fuel in the tank? FPR?

[TiTAN]

is the ECU saying 95% duty on the injectors or 95 on the fuel map?

[joeyjoejoejuniorshabadoo]

as above tai... i'd be looking at things in the fuel system before the injectors that are holding them back... 480 cc injectors can flow 260rwkw

as stevo suggested but also fpr, fuel filter and pump relay

[666DAN]

Did they leave the standard fuel reg on, pump side just under the inside of the fuel tank cap?

[candy33]

Im not really sure, but my brother (whos tuning the car) said the injectors are at 95% duty cycle via what it says on the Tuning software.

I find it odd as i had 240awkws at 15psi using stock injectors and stock pump? now i've upgraded and only slightly done better?

Theres lots of fuel in the tank, lines seem to be unhindered, as i never touched it since my stock setup.. might have to check the fuel filter. Is there a way of knowing if its blocked?

Just that its running at 95% at the top end of the rev range, and cannot boost or tune further until this problem is resolved.

Thanks for the help guys

Tai

[candy33]

Did they leave the standard fuel reg on, pump side just under the inside of the fuel tank cap?

I believe they did, I remember the pump i brought had the gold colored reg thing still attached to it, and they removed that one and used the one that was already on the stock pump i think?

[Beer Baron]

there is no reg attached to the pump. and no reg in the fuel tank so i'm not sure what 666Dan is talking about?

what is the AFR? you can make any injector max out at any power level if you don't mind AFRs around 9:1! lol. more info needed to sort through this one I think.

[666DAN]

I believe they did, I remember the pump i brought had the gold coloured reg still attached to it, and they removed that one and used the one that was already on the stock pump i think?

They should have retained the brass one for sure, the stock one is a plastic piece of crap

Richard, my pump had a reg on it....purple plastic thing right up the top of the outgoing fuel line, I got a nice replacement one with the GTR pump.

[Beer Baron]

there is no such thing in an R32 GTR. there is an anti drain back valve on the pump. but there is only one fuel pressure reg in the whole system, and it's on the return end of the fuel rail.

[candy33]

I'll have to find out more info, but just got off the fone with my bro he said the AFR's are around the 12-13 (safe) all the way throught the rev range on the 13psi its at now, but once boosted more it wants to lean out.. so its set on 13psi.

He's tuned heaps of cars alot more powerful than mine, so i don't doubt him.

[666DAN]

OK...well there is one in the R34, I had to call Nissan to check what it was and they said it was a primary fuel reg on the feed line (it's definately on the feed in my car)

I even just checked the workshop manual, complete break down of the fuel pump side, shows the two halves of the pipe but doesn't show the reg thing in line....bloody Nissan left it out *shakes fist*

[N1GTR]

So stock fuel reg?

Here's what ive added to a stock fuel system in a gtr, compare your parts;

-Intank 044 bosch

-SARD f.p.r.

-SARD injectors (same)

Just by doing that it did 355kw atw at something like (from memory, probably wrong) 70% duty cycle. I remember the fuel system had a shitload more in it

As BB said, more info

[Beer Baron]

OK...well there is one in the R34, I had to call Nissan to check what it was and they said it was a primary fuel reg on the feed line (it's definately on the feed in my car)

well there is some gold dangly thing, but it's not a reg like the other one is. it has no pressure feed. and it's on the supply line. so if anything it restricts flow (and if it was doing that it would LOWER pressure in the feed after it). but most likely it's anti drain back valve.

[TiTAN]

candy33, i would get your brother to check that he has setup the injectors correctly on the ECU, he could be confusing a value of 95 on the fuel map as being 95% duty. what is the master value set to? (XXms)

on this image where is it showing 95?

[Beer Baron]

basically with the sard pump, stock lines, stock wiring, stock reg and sard injectors you should be able to support 350kw+. so something is wrong. either the software is not accurate and you don't really have 95% duty, or you do have 95% duty, but don't need to (ie your AFR is stupid rich), or something is not installed correctly.

[candy33]

I will get you more info soon guys.

Yes its running stock fuel reg, fuel rail and lines.

My brothers have built and tuned several other GTR's using the stock fuel reg, fuel rail and lines for near 400awkws, so i can't seem to see how that could be my problem.

He did say that my turbo ramps up really quick with about 80% of the power coming in the vicinity of a thousand rpm, which could be the cause of it not keeping up.

But yeah i'll stop speculating and do more investigating.

Thanks guys

[candy33]

candy33, i would get your brother to check that he has setup the injectors correctly on the ECU, he could be confusing a value of 95 on the fuel map as being 95% duty. what is the master value set to? (XXms)

on this image where is it showing 95?

Thanks for that Titan, i will find out for you asap.

Cheers

[666DAN]

well there is some gold dangly thing, but it's not a reg like the other one is. it has no pressure feed. and it's on the supply line. so if anything it restricts flow (and if it was doing that it would LOWER pressure in the feed after it). but most likely it's anti drain back valve.

Maybe regulator was the wrong wording, yes it's a flow restrictor. Most people just bugger the thing off as it's got no place in a real car

I was thinking in terms of it restricting fuel supply into the lines, the injectors not getting the pressure behind them as they're draining the post restrictor fuel off too quickly, as a result low line pressure is seeing duty cycle increase as it's having to be high to meet the challenge.

[R31Nismoid]

First things first

Stock fuel reg, rail & lines are fine for massive power, so its not a problem there in that sense

So if the injectors are maxing out, something is impeading flow.

I would look at

1. Pump voltage - is the pump getting the required volts (stock wiring is NO good).

2. Fuel Filter - is it a decent flowing one? Is the fuel filter perhaps blocked?

3. Fuel Hose - has it been changed at some point? Is it large enough etc etc.

4. Fuel Pump - is it mounted correctly? Is there 110% certainty there is nothing potentially blocking the pickup?

5. Fuel lines - Are some of them bent/kinked perhaps which would possibly cause problems?

6. Fuel pressure - Has this been checked and confirmed to be correct?

Check those things, and also the other stuff about the "95" value actually being 95% Duty.