Jump to content
SAU Community

Decresing Fuel Comsumption

Dizmo

By Dizmo,
in Engines & Forced Induction

 Share

Recommended Posts

Dizmo Enthusiast

Dizmo

Posted
Posted

The other day i cleaned my AFM with contact cleaner and it has made my fuel consumption increase. before i cleaned it i was getting 420km outta a tank, now its down to 330km (same drivin style). I have a rb20det, stock ecu, not cat, fmic, r43 turbo and 7psi boost.

Can i lean out the mixture using the stock ecu?

What are some ways of decreasing fuel economy? (dont say lift up the right foot coz i drive like a granny mostly)

Link to comment
https://www.sau.com.au/forums/topic/118977-decresing-fuel-comsumption/
Share on other sites
paulr33 Grand Master

paulr33

Posted
Posted

ecu remap or piggyback computer

remap or apexi safc

you need to bend the afm signal to make the ecu think more air is coming into the system than actually is, so it leans it out based around the "apparent" amount of air thats coming report (reported by the afm bender)

dangerous_daveo Grand Master

dangerous_daveo

Posted
Posted

I was getting 500+kms to a tank before a chip, its now 550kms+ to a tank out of my rb20 cefiro on 12psi on an rb20 turbo.

I think you have another issue that needs to be addressed to sort out your fuel economy. I cant see how a piggy back or chip can solve the problem straight off. So you sort whatever it is out first, then go from there.

paulr33 Grand Master

paulr33

Posted
Posted

dont you dare use a resistor. get it tuned properly. youll certainly put the engine at great risk by using a stuid method such as an inline resistor.

either

1) get an safc and get it tuned

2) get a remapped ecu and get it tuned

3) get an aftermarket ecu and get it tuned

you should also make sure your onboard oxygen sensor is working and has been replaced recently (they last around 50,000k's)

rob82 Mentor

rob82

Posted
Posted
you say that you don't have a cat running in between the exhaust system..

I recommend you put it back in.. firstly you won't get a fine and it should give you better fuel economy

How the f**k does a cat give you better fuel economy???

Dude just take it to a mechanic that knows what he's doing. Get him to check the base timing is correct and that the 02 sensor is trimming, check fuel flow and pressure(just for safety), have the injectors cleaned and then get a chip if it is still shite.

The problem with getting buildup on your MAF is that it desensitises the hot wire element therefore it reads that there is less air coming in and leans the engine out. Once you cleaned it it went back to being typically nissan programming rich.

Busky2k Veteran

Busky2k

Posted
Posted

SAFC wont help with fuel economy. If you lean it out on low loads and RPM, it doesnt take long for the ECU to learn around it and attempt to maintain your AFRs at 14.7.

Its easily demonstratable if you have a wideband as I was doing my own testing with an SAFC a while ago.

I would replace your O2 sensor and then do an ECU reset. What did you clean your AFM with? Please don't say WD40!

Dizmo Enthusiast

Dizmo

Posted
  • Author
Posted

I cleaned the afm with contact cleaner.

should i replace the O2 sensor thats on the exhaust?

HAving no cat doesnt improve fuel economy it just there to pass emissions.

Can the stock ecu be 'tweaked' to improve the mapping?

my_gtr32 Collaborator

my_gtr32

Posted
Posted

What he said.

Try and reset you're ecu first. Factory programming will be rich but it's possible that a reset may help things. Apparently after a reset, as the ecu re-learns it makes larger adjustments at first, then only slight changes after that. Dissconnect you're battery, step on the brake pedal a few times then reconnect the battery or leave it off for longer. Should do the trick. It can't hurt and it's free.

How the f**k does a cat give you better fuel economy???

Dude just take it to a mechanic that knows what he's doing. Get him to check the base timing is correct and that the 02 sensor is trimming, check fuel flow and pressure(just for safety), have the injectors cleaned and then get a chip if it is still shite.

The problem with getting buildup on your MAF is that it desensitises the hot wire element therefore it reads that there is less air coming in and leans the engine out. Once you cleaned it it went back to being typically nissan programming rich.

  • 2 weeks later...
RANDY Veteran

RANDY

Posted
Posted
you need to bend the afm signal to make the ecu think more air is coming into the system than actually is, so it leans it out based around the "apparent" amount of air thats coming report (reported by the afm bender)

Surely this would be the other way round? For better economy, you'd want the ECU thinking it's getting less air, so it squirts less fuel into the mix? More air would call for more fuel normally, right?

I would have guessed that if you clean the crap off the wire in the AFM, the wire is more exposed to the actual air coming in, which would cool the wire down and tell the ECU to squirt more fuel. (as the ECU measures the voltage of the wire based on the heat the wire retains from the voltage being applied to it)

If the wire is protected by gunk, it would stay warmer and not see so much air, and the ECU will give it less fuel to mix with?

Correct me where i'm wrong, but i've cleaned everything on my car, and I get BAD economy... I was really hoping a SAFC would help fix this.

RB30-POWER Mentor

RB30-POWER

Posted
Posted

Give it a general tune up first.

New plugs, new O2 sensor, check timing, clean injectors, fit a new air filter element into the airbox. (piss of pod filter if you have one).

Check that the water temp sensor is reading/working correctly as this is used for cold start enrichment.

And see how you go.

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      All I hear is ROADTRIP!
    • sunsetR33
      Unpeeling the Orange

      By sunsetR33 · Posted

      Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
    • Kapr
      What brakes on R34 GTT(Europe)

      By Kapr · Posted

      No those pads are DBA too  but they have colors too. I look at the and imo the green "street" are the best.
    • wizlb
      Who has a Infiniti Q60, Q50 (V37)?

      By wizlb · Posted

      I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
    • Kinkstaah
      Starting again

      By Kinkstaah · Posted

      Yea - I mean I've seen my fuel pump which is decades old and uh, while I'm not saying this with real knowledge... but I sure get the ick at using anything in the fuel system that produced the state of that pump. Many years ago I went through multiple pumps (and strainers) before I dropped the tank to clean it out with extreme violence. I'm talking the car would do maybe 50km before coming to a halt, which resulted in me cleaning out the filter with some brake cleaner and going on my way. None of my stuff ever looked like what came out of your fuel tank. I don't think I'd be happy with it unless every single component was replaced (or at least checked/cleaned/confirmed to be clean here).
×
×
  • Create New...