Jump to content


Photo

Wideband-Air/fuel Ratio Numbers


  • Please log in to reply
3 replies to this topic

#1 brivinci

brivinci

    One Carb Or Two?

  • Members
  • PipPipPipPipPipPipPip
  • 1,095 posts
  • Location: New Jersey

Posted 20 March 2018 - 03:30 AM

Hey guys, wondering if anyone has experience using a wideband scanner on their injection mini? My boss just bought a Innotate Motorsport LM 2 digital air/fuel meter and gave it to me to setup and test. He bought the added rear sniffer that goes into then tailpipe as I dont have a dedicated port for this sensor. My SPi is not running a cat currently.

So, I fired it all up and start the car. Cold, it idles around 14-15 AFR. After I had to warm I did a pull from 1st through 3rd, to about 5.5k rpm. The AFR starts around 14.7 (which is where it should be from what Ive read) and dips down to lower 13s when up in the revs. I assumed that was going to be the case with the mods I have. Under regular cruising, the AFR stays close to the 14.7 but then at idle (Now warm and after two pulls, the idle afr is up around 20-30 AFR.

Just wondering if others have used one of these and have any opions on the above. Next time I run this I will capture a log.

#2 timmy850

timmy850

    Up Into Fourth

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPip
  • 2,976 posts
  • Location: NSW, Australia
  • Local Club: MITG

Posted 20 March 2018 - 04:47 AM

You might not get super accurate results at idle with the sender at the end of the exhaust pipe. You can get fresh air mixing with the exhaust which can indicate lean. 



#3 Sprocket

Sprocket

    Great on Injection faults

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 7,266 posts
  • Location: Warrington
  • Local Club: Manchester Minis

Posted 20 March 2018 - 08:12 AM

The numbers you see are fairly normal, except for the warm idle. At those sorts of numbers, the engine just wouldn't run and even if it did it would be absolutely gutless, likely stall when you depress the throttle, so what you are probably looking at is air being drawn into the tailpipe. Yo need to make up an addapter for the sensor that can go deep into the exhaust, as any measurement near the tailpipe especially at idle  can be skewed by reversion in the exhaust.

 

That said, if you have an exhaust leak, the same could be true, but the numbers you report seem a little high for this.

 

I've been tempted for a while no to install a wideband controller and use the narrow band output to signal the ECU, but I don't have the SPi anymore.



#4 brivinci

brivinci

    One Carb Or Two?

  • Members
  • PipPipPipPipPipPipPip
  • 1,095 posts
  • Location: New Jersey

Posted 22 March 2018 - 01:53 AM

Yes, this was all just a test. I was actually planning on getting a new Maniflow LCB (their updated design) to replace my old unit and have them supply it with a bung welded into the Y-pipe/collector. Initially, I was thinking of moving my stock Lambda there but it would be a bad idea to run this in there first to see what it reads. There is a way to hook up this controller to the ECU...but its not mine nor is it a gauge type. It is a small, hand held unit. 

 

If I did do that, I believe it would do the same as if I was to be running the MEMs analyzer...aside for the wideband data.






1 user(s) are reading this topic

0 members, 1 guests, 0 anonymous users