Jump to content
SAU Community

R33 Rb25Det Running Rich On Idle

Dose Pipe Sutututu
 Share

Recommended Posts

Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted

Hi All,

So recently I've connected up an wideband O2 with narrowband simulation (Innovate MTX-L). I'm currently using the narrowband output from the wideband and connected to the factory ECU deleting the existing factory narrowband sensor.

To my surprise, the motor isn't idling at stoich which is strange it averages around 12.7 A/F when warm.

There are no vacuum leaks, no vented catch cans or anything as such, and I believe the coolant temp sensor is working because when it's disconnected the car won't start.

No real biggie, as I will be getting a standalone soon enough, but just curious on why the factory ECU runs so damn rich on idle? On full song at 0.7bar it drops to 10.5 A/F which is expected of a stock ECU.

This is the first time I've put a wideband to analyse A/F on a factory ECU, so I'm curious to see if that's correct? I always thought it should be idling on stoich, and even on light throttle/cruise the A/Fs are averaging at 13.3.

I might try cleaning the AFM this weekend and see if that makes any difference (I highly doubt it).

Any other ideas?

Link to comment
https://www.sau.com.au/forums/topic/429151-r33-rb25det-running-rich-on-idle/
Share on other sites
Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
  • Author
Posted

are you getting these figures when the engine is cold or warm?

After a nice drive, thermostat is fully opened idle is at 650 rpm, I get about 12.7 A/F. On a cold start up I'm getting about 11.4 A/F. Like mentioned before, I'm not too concerned about it as I will be getting a new ECU soon enough.

Just more of a curious thing.

AngryRB Grand Master

AngryRB

Posted
Posted

After a nice drive, thermostat is fully opened idle is at 650 rpm, I get about 12.7 A/F. On a cold start up I'm getting about 11.4 A/F. Like mentioned before, I'm not too concerned about it as I will be getting a new ECU soon enough.

Just more of a curious thing.

I can remember mine running rich with a stock ecu, used to puff out a little black smoke just reversing but was never a problem.
Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
  • Author
Posted

I'll try and disconnect the narrowband simulation to the ECU and see what it does. My original O2 was dead and was disconnected a few days after I bought the car due to idle hunts.

Instead of replacing a stock O2, I decided to for a wideband with narrowband simulation because I'm going to get a full standalone soon enough.

I'll try and recal the O2 too and see what's going on and also borrow my mate's handheld Innovate wideband and see what's going on.

Oh yeah and the sensor is mounted just before the Cat

Missileman Veteran

Missileman

Posted
Posted

Just for you Jonnie xxxooo

the wavy green is the o2 doing it thing, the spike is decal fuel cut.

Notice the lag between throttle V+ and RPM and LAFR, well that how long it takes for my Tech Edge to log what my foot is doing ;)

gallery_89296_5394_207220.jpg

Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
  • Author
Posted

that lag time isn't too bad!

anyways, just something interesting, took my car on the track yesterday and the consumption was hideous!! :yucky:

84kms per 25L

flat foot down the straight on wakefield and she was 10.1 A/F

On another note, I did an ECU error code check, got error 13 = water temp sensor..

explains why it's overly rich!

Missileman Veteran

Missileman

Posted
Posted

that lag time isn't too bad!

flat foot down the straight on wakefield and she was 10.1 A/F

On another note, I did an ECU error code check, got error 13 = water temp sensor..

explains why it's overly rich!

Had a feeling the temp sensor was reading incorrectly, 10:1 is fairly normal for the top right corner of the stock fuel map. I've started slowly taking fuel out of mine there, and it's still in the 10.xx:1 range. Put my new 440CC EV14 injectors in tomorrow so I expect my economy will be shite for a couple of week while I attempt a home tune.

Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
  • Author
Posted

Haha too easy, injectors in rough tune done, made it home ok, beer O'clock time :)

lol.. isn't really rocket science right? just as long as you're getting the right A/F you'll be sweet.

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

    • QB6SAGR
      Tein Circuit Master- rebuild worth it?

      By QB6SAGR · Posted

      Thanks guys,  Yeah I should at least have them dynoed, at least then I know what I've got as a starting point.  The springs on these are hard as rocks. I vaguely remember Russman saying he was going to sell the shocks to me with the rocks fitted, as he was keeping the softer springs for his new setup.  I didn't click at the time but of course that was to let me know the shock/spring wouldn't be matched.  I also remember pricing up new springs around 2014-15, but, house, money etc. it never happened. So that was another reason to have them rebuilt. I have rebuilt the forks on many motorcycles so I think I could handle the seals on these easily enough, but getting the valving right would be a rabbit hole I cbf exploring.  Duncan, interesting to hear RP was tuning these back then. I might give them a call.  In the mean time I have been busy fitting sway bars. The Whiteline rear sway bar I purchased 15 years ago finally got fitted, along with the Whiteline front bar that showed up last week. Just waiting on new links for the front sway bar to finish that off.  And my spare set of advan AVS VS5's should be back from the powder coaters in a Pearl White finish sometime this week, with a set of Hankook RS4's lined up for fitting.  And then I just have all the suspension bushes to do. A comprehensive kit is on the way... Lots to do before the Ararat hill climb. Cheers guys 🍻   
    • funkymonkey
      Howdy Y'all

      By funkymonkey · Posted

      Nice car! I’m glad folks in the US have gotten past the FnF and are buying real cool cars like the 260RS I was with a bunch of mates in Portland about a year ago and spotted a green Stagea (just a regular 2.5T AWD) parked about 2 blocks away and they were like “a what?” So I made a bet with them for a round of beers and said “ok one of you run down there and tell me if the steering wheel is on the correct side” 5 mins later the American comes trudging back up the hill and goes “he’s right guys. Ok what beer do you want?”
    • Dose Pipe Sutututu
      Starting again

      By Dose Pipe Sutututu · Posted

      Should replace OR drop the tank, give it's good clean. Might be worth replacing that entire fuel level/pump/cradle thing with this: https://frenchysperformancegarage.com/products/fpg-s13-180sx-r32gtst-single-pump-hanger-kit-billet-hat-6-v3-fpg-089?gQT=2  
    • R33_Guy
      Speed Sensor replacement

      By R33_Guy · Posted

      Thank you so much for the help
    • GTSBoy
      Speed Sensor replacement

      By GTSBoy · Posted

      Yes it is ATF. I quote @Duncan "it takes a good synthentic auto trans fluid like Castrol Transmax Z" It's not a diff. It's a transfer case. Totally different thing. Yes, fluid will come out the sender hole. No you do not really need to drain it. Just pull the old, quickly poke the new, clean up and top up. But realistically, you should probably take the opportunity to change it anyway.
×
×
  • Create New...