Jump to content
SAU Community

Recommended Posts

I have a unknow part inline with my fuel return line it is located in the same area as the stock fuel filter

it looks like some sort of regulator with no ajustments. I have a Aeromotive fuel regulator and i was

wondering if this part would affect the pressure as it is inline after the ajustable fuel reg.

Also do i need it as i cant find any info on it or what it is

thanks Sam.....

Link to comment
https://www.sau.com.au/forums/topic/389549-unknown-fuel-line-component/
Share on other sites

Hi thanks for the reply i dint see any reply yesterday si i have allready removed and tossed it into the bin

Since i removed it setting the fuel pressure is much easier now i have to find the second one and ill get rid of that as well

quote name='SargeRX8' timestamp='1327672838' post='6207247']

It's a dampener, leave it there. There is another one in the fuel tank.

heres some stuff i googled earlier, I thought it best to keep it but happy to stand corrected..

Like most mechanical systems, the fuel system has resonances related to the length of the components and the speed which the pressure waves travel in the lines. The injector fuel rail is particularly susceptible because it has two closed ends forming a nice resonator (standing waves with high and low pressure along the rail), and a bunch of vibrating injectors to excite the resonance. The dampener de-Q's the resonator, it reduces the ratio of stored energy to energy dissipated. Any mechanical system of this nature needs to have it resonances managed, which is why all the auto manufacturers use them.

There was a fuel system engineer much smarter than us who decided a fuel pulsation damper was needed.

Without an FPD the fuel pressure will fluctuate (at a frequency higher than your fuel pressure gauge is capable of displaying). If the fuel pressure is fluctuating everytime the injectors open and close then they are not metering fuel as accurately as they could be.

Apparently some aftermarket FPRs have them built in though. :unsure:

Hi thanks for your input after reading your post it makes sense so i went through the rubbish bin found said dampener and fitted it back to where it should be

The reason i have been playing with fuel pressure my motor is now run in i know most people tell me it was ready to flog after a couple of hundred kms. But im old school

I had the fuel pressure set a bit low 30psi for the first 5000kms also timing was aset at 10deg for that time also noticed that spark plugs were still pretty clean. After 5000kms

i wanted to set everything as per std si i upped the timing to 15 deg fuel pressure at 42psi so off i went for a drive was hopeing to put a gin on my face after sooo long but come

home a litle dissapointed.What happened drove car untill everything warmed up got on to my local back road and got on the thunder stick. Stuck me to the seat right up to around 4500rpm

then starts misfiring almost sounds like the engine is flooding it keeps misfiring for a few hundred meters then comes good ran it this way gently for 3 days then took out the plugs

and they are black and sooty. I thought it might be the plugs NGK Platinum so i put a new set of Denso iridium plugs in still doing the same.

Here are the engine stats: New Engine: ,,Hi-flow Turbo:,,Coil Paks:,,Plugs:,,Fuel Pump:,, 80MM Throttle Body + greddy intake manifold :

,,Fuel Regulator

Compresson: 1=163psi

2=165psi

3=160psi

4=165psi

5=163psi

6=160psi

Changes from old setup: "MANIFOLD" "THROTTLE BODY" "8.5.1 COMP FORGED PISTONS +40" New Fuel Pump+Coilpaks

Plugs gapped at .8mm Engine idle 650rpm with throttle switch disconnected 15deg timing 750rpm with switch connected still 15deg stat timing.

When i move the ajustment screw to set the pressure to 42psi with vac line to reg disconected just before it gets to 42psi the pressure droppes to 38psi on the gauge and wont ajust any higher

unless i touch the throttle a little then the pressure goes to around 50psi then back to38psi i have ajusted it so that im getting 42psi with thottle moved a little

but it stll drops back to 38psi does not move when vac line plugged back on.

Can anyone shed some light on the problem as i need it to run ok before i get new ecu and have it tuned.

I LIVE 3 HRS AWAY FROM NEAREST DYNO

PS. SORRY TO MAKE THIS INTO A SHORT NOVEL

heres some stuff i googled earlier, I thought it best to keep it but happy to stand corrected..

Like most mechanical systems, the fuel system has resonances related to the length of the components and the speed which the pressure waves travel in the lines. The injector fuel rail is particularly susceptible because it has two closed ends forming a nice resonator (standing waves with high and low pressure along the rail), and a bunch of vibrating injectors to excite the resonance. The dampener de-Q's the resonator, it reduces the ratio of stored energy to energy dissipated. Any mechanical system of this nature needs to have it resonances managed, which is why all the auto manufacturers use them.

There was a fuel system engineer much smarter than us who decided a fuel pulsation damper was needed.

Without an FPD the fuel pressure will fluctuate (at a frequency higher than your fuel pressure gauge is capable of displaying). If the fuel pressure is fluctuating everytime the injectors open and close then they are not metering fuel as accurately as they could be.

Apparently some aftermarket FPRs have them built in though. :unsure:

Your problem is the tune. So many changes! - get that new ecu and drive very carefully to the tuner. I am very old school - leave the fpr standard, run in should take 30 minutes - get to your tuner asap.

You don't mention new injectors and, if you are not getting a Link or similar, better afm.

Yep i know its never going to work properly without some sort of ecu management

I have a Emange Blue+ Z32 AFM 3bar pressure sensor that i was going to use but Im in 2 minds over it

So many ecu choices then people to tune them i was told today the dyno place in nowra shut shop over

a year ago plus id rather go to sydney to get it tuned spent to much money not to.

Thanks for all your inputs ill do some researching on ecu's and who tunes them

Correct me if I'm wrong, but you're setting the fuel pressure with the engine running. From what I understand you set it while the engine is turned off but fuel pump running.

Also, why ditch the factory reg? I'd go buy a new factory one if I were you and be done with it.

Hi Steve thanks for your reply phoned simon and going to drop into his workshop on the way home

from work this week thanks sure beats going all the way to sydney.

Definitely open, Simon 0427 387 842

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Well, I can recommend the partial AV system translation CD I ordered from Car Audio Workshop in NZ. Whilst it didn't address the date issue, it has conveniently translated on-screen menu items into English, and now allows the GPS-received time to be offset in hours rather than minutes, so I can display Eastern Australian time accurately ( and bump it by another hour when daylight savings starts ).
    • Yuh, if it's 45°C outside, my car is driving in it.
    • I'd be curious to hear more. Otherwise, have you driven a modern x-trail? I wonder how it compares. Here in Australia they are/were popular for rentals and fleet vehicles. I have been in some and my impression was they are bad. But, this may have been very different in the 2000s at a good trim level. Twenty years is plenty of time to make the model worse. I do very much agree with the 2 silver cars in the garage approach. But, not driving because it's too hot would not leave a lot of time in the year for many Australians. I don't think you need to worry too much unless the car has actual issues with overheating. 
    • Back again. I returned to Japan in Jul/Aug to spend time with the car on my birthday and remind myself what all the sacrifice and compromise is for. It happened to line up with the monthly morning meet in Okutama, which I have been wanting to go to for a long time. It's a unique event at a unique spot with really rare, interesting, and quirky cars. It's where all the oldheads and OGs gather. The nighttime scene at DKF certainly has its place and should be experienced if you're into cars, but there's too much bad attention and negativity around it now. IMO the better time is Sunday morning at DKF or Okutama; it's more chill and relaxed. I'm glad I was finally able to go, but not sure it's worth the drive from all the way from Nagoya immediately the day before, unless I was already staying in Tokyo for the days right before the meet, because you have to wake up quite early to make it in time. Funnily enough though I didn't drive the car all that much this trip because it was just too damn hot. While there were zero issues and running temps were nominal and the A/C was strong, RBs already run crazy hot as it is. Sure, it took it all like a champ but something about driving these cars in the ridiculous heat/humidity bothers me and makes me feel like I'm asking too much of it. I'm just me being weird and treating the car like a living thing with feelings; I'm mechanically sympathetic to a fault. Instead I was mainly driving something else around - a KX4(silver) 2001 X-Trail GT, that I acquired in May. There's a few different flavors to choose from with Xs, but visually it's the Nissan version of the Honda CR-V. Mechanically it's a whole different story as this, being the top-trim GT, has an SR20VET mated to a four-speed auto and full-time AWD! It was a very affordable buy in exceptional condition inside and out, with very low mileage...only 48k kms. Most likely it was owned by an older person who kept it garaged and well-maintained, so I'm really happy with how it all worked out. It literally needs zero attention at the moment, albeit except for some minor visual touch-ups. I wanted something quirky, interesting, and practical and for sure it handily delivers on all three of those aspects. I was immediately able to utilize the cargo and passenger capacity to its full extent. It's a lot of fun to drive and is quite punchy through 1st and 2nd. It's very unassuming -in the twisty bits it's a lot more composed than one would think at a glance- and it'll be even better once I get better tires on it(yes, it's an SUV but still a little boat-y for my liking). So...now I have two golden-era Nissans in silver. One sports car and one that does everything else; the perfect two-car solution I think👍 The rest of the trip...I was able to turn my stressed brain off and enjoy it, although I didn't quite get to do as much as I thought. I did some interesting things, met some interesting people, and happened into some interesting situations however, that's all for another post though only if people really want to know. Project-wise, I went back to Mine's again to discuss more plans and am hoping to wrap that up real soon; keep watching this space if that interests you. Additionally, while working in the tormenting sweatbox that is the warehouse, I was able to organize most of the myriad of parts that my friend is storing for me along with the cars, and the 34 has a nice little spot carved out for it: And since it can get so stupid hot in there, that made it all the more easy -after I was standing there looking at the car and said 'f**k it'- to finally remove all the damn gauges that have mostly been an eyesore all this time. Huzzah. The heat basically makes the adhesive backing on the gauge mounts more pliable to work with, so it was far less stressful getting this done. I didn't fully clean it up or chase the wiring though; that will happen once I have the car in closer possession. Another major reason to remove all that stuff is to give people less reasons to get in my car and steal s**t while it's being exported/imported when/if the time comes, which leads us to my next point... ...and that is even though it's time in Japan is technically almost up since it's a November car and the X would be coming in March, I'm still not entirely sure where my life and career is headed; I don't really know what the future looks like and where I'm going to end up. I feel there's a great deal of uncertainty with me and as a result of that, it feels like I'm at a crossroads moreso now than any point in my life thus far and there are some choices I need to make. Yes, I've had some years to consider things and prepare myself, however too much has happened in that time to maintain confidence and everything feels so up in the air; tenuous one might say. Simply put, there's just too much nonsense going on right now from multiple vectors. Admittedly, I'm struggling to stay in the game and keep my eyes on the prize. So much so in fact, that very recently I came the closest I ever have before to calling it quits outright; selling everything and moving on and not looking back. The astute among you will pick up on key subtext within this paragraph. In the meantime I've still managed to slowly acquire some final bits for the car, but it feels nice knowing there's not much left to get and I'm almost across that finish line; I have almost everything I'll ever want for my interpretation and expression on what it is I think an R34 should be. 'til later.
    • Thanks for that, hadn’t used my brain enough to think about that. 
×
×
  • Create New...