Jump to content
SAU Community

Recommended Posts

Hi chaps,

It seems whenever I take my car to the local track (Barbagallo), I experience the following:

  • fuel surge when tank is approx <60% full
  • high fuel consumption - roughly 6 laps will consume 1/4 of the tank

Additionally, when at the tuners, they said that the injectors are maxed out; they're not completely sure what the reason is. Initially it was believed to be a lazy pump, however after swapping that out, it seems to still be the same.

My fuel setup (and other possibly pertinent information) is as follows

  • R34 GT-Four (not sure if they run a different style fuel tank, or smaller fuel hosing, given it used to be an N/A car from factory)
  • RB26DETT
  • Approx 515hp on a hub dyno, which is usually reading a bit higher than roller dynos
  • Running E85
  • Deatschwerks 1200cc injectors
  • Walbro 460lph intank fuel pump
  • Standard fuel rail and FPR
  • Unsure of fuel filter, I don't think it's anything fancy, but has been changed a couple of times since switching to E85

Since swapping fuel pumps, not completely sure if the surging is still present, as I kept the fuel topped up each time I went out; however the workshop said the previous pump was secured well, and was low down, so there was no reason for it to surge previously.

I am considering putting in a fuel surge tank, -10 micron filter, new fuel rail and an adjustable FPR to try and fix all the above items, however just wanted to see if someone has any ideas before I embark down this road.

The other strange thing is that I know another car which is exactly the same fuel pump and injectors as me, however is sitting at 100hp more with breathing room on the injectors, and another car which has same injectors (different fuel pump), but is over 700hp

Thanks!

You should have heaps of fuel for that power level. Fuel rail and FPR "should " be up to it. Have you tested the fuel pressure? Maybe you have struck a dud pump. Have you wired the pump for full battery voltage? Have you seen the afr chart? Is it possible that it is a problem with the tune?

Hey guys, thanks for that!

I don't have any fuel pressure gauges on it, that's something the tuner did and said they had maxed out

Pump is wired up for full voltage, the AFRs were previously a bit on the lean end up top, which has now been rectified so that they're "safe", but I don't have a copy of it sorry ...

The tuner is very good, I don't think there's any issue on that front

Sorry for the noob question, but I if I had a fuel pressure gauge on it, and for example the fuel filter is blocked, that would then be able to tell me that the filter is blocked and the injectors are over-working/hitting max duty-cycle, due to the reduced fuel flow (given by the pressure)?

My R34 has had issues with fuel filters before. Changed to an Earls and changed that when it became blocked, but I noticed this by the car running lean under power, which coincidentally was about the same amount of power you have :P

All it took for me was to run one tank of 98 and switching back to E85 to see my filter full of stuff. Pretty much want to change it any time I do an oil change now, I would lose my mind if I didn't have a wideband that will cut the engine if the event of a lean condition as I'm super paranoid about fuel filters now.

those are 1000cc with normal rail pressures, those DW are a 4 or 5 bar base 1200cc rating.

your power is around 390rwkw and is around right for getting close to max. (390-420)

It's interesting how DW and other brands feel the need to rate injectors at higher pressure to make them sound larger than they are.

My 1000's are actually 5000cc at 100 bar rail pressure. ;)

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

    • Thanks for that, I'll check it all out. I can always do the brakes last anyway if its a problem.  The 16's are super cool, if they do fit I'll cruise around with them for a bit.  
    • Well, that's kinda the point. The calipers might interfere with the inside of the barrels 16" rims are only about 14" inside the barrels, which is ~350mm, and 334mm rotors only leave about 8mm outboard for the caliper before you get to 350, And.... that;s not gunna be enough. If the rims have a larger ID than that, you might sneak it in. I'd be putting a measuring stick inside the wheel and eyeballing the extra required for the caliper outboard of the rotor before committing to bolting it all on.
    • OK, so again it has been a bit of a break but it was around researching what had been done since I didn't have access to Neil's records and not everything is obvious without pulling stuff apart. Happily the guy who assembled the engine had kept reasonable records, so we now know the final spec is: Bottom end: Standard block and crank Ross 86.5mm forgies, 9:1 compression Spool forged rods Standard main bolts Oil pump Spool billet gears in standard housing Aeroflow extended and baffled sump Head Freshly rebuilt standard head with new 80lb valve springs Mild porting/port match Head oil feed restrictor VCT disabled Tighe 805C reground cams (255 duration, 8.93 lift)  Adjustable cam gears on inlet/exhaust Standard head bolts, gasket not confirmed but assumed MLS External 555cc Nismo injectors Z32 AFM Bosch 023 Intank fuel pump Garret 2871 (factory housings and manifold) Hypertune FFP plenum with standard throttle   Time to book in a trip to Unigroup
    • I forgot about my shiny new plates!
    • Well, apparently they do fit, however this wont be a problem if not because the car will be stationary while i do the suspension work. I was just going to use the 16's to roll the old girl around if I needed to. I just need to get the E90 back on the road first. Yes! I'm a believer! 🙌 So, I contacted them because the site kinda sucks and I was really confused about what I'd need. They put together a package for me and because I was spraying all the seat surfaces and not doing spot fixes I decided not to send them a headrest to colour match, I just used their colour on file (and it was spot on).  I got some heavy duty cleaner, 1L of colour, a small bottle of dye hardener and a small bottle of the dye top coat. I also got a spray gun as I needed a larger nozzle than the gun I had and it was only $40 extra. From memory the total was ~$450 ish. Its not cheap but the result is awesome. They did add repair bits and pieces to the quote originally and the cost came down significantly when I said I didn't need any repair products. I did it over a weekend. The only issues I had were my own; I forgot to mix the hardener into the dye two coats but I had enough dye for 2 more coats with the hardener. I also just used up all the dye because why not and i rushed the last coat which gave me some runs. Thankfully the runs are under the headrests. The gun pattern wasn't great, very round and would have been better if it was a line. It made it a little tricky to get consistent coverage and I think having done the extra coats probably helped conceal any coverage issues. I contacted them again a few months later so I could get our X5 done (who the f**k thought white leather was a good idea for a family car?!) and they said they had some training to do in Sydney and I could get a reduced rate on the leather fix in the X5 if I let them demo their product on our car. So I agreed. When I took Bec in the E39 to pick it up, I showed them the job I'd done in my car and they were all (students included) really impressed. Note that they said the runs I created could be fixed easily at the time with a brush or an air compressor gun. So, now with the two cars done I can absolutely recommend Colourlock.  I'll take pics of both interiors and create a new thread.
×
×
  • Create New...