Not enough O2 correction

[tonydee64]

I finally got my car running and thought I had an artificial lean idle condition of 15.94 (the max lean) with black smoke bellowing from my exhaust. I took the car out of closed loop mode and manually backed off the values in the base VE table and adjusted the throttle blades which stopped the black smoke, which also produced a smooth steady idle. Now, the closed loop is set to kick in at slightly above idle and not to turn back off at a few hundred RPM under idle. To make a long story short I have run several logs and just can't get the O2 sensor to take out enough fuel to bring the actual A/F to the Target A/F. I have target A/F set for 14.1 in that area and the closest I can get is somewhere between 12.6 - 12.9... I have adjusted the closed loop gain all the up to 50 which did get me a little closer, but I have 83lb. injectors and shouldn't need that much gain.. right? I even tried to adjust the Max Closed Loop Step but it would only let me go to 10.

All of my global parameters are correct for my application.

The biggest question I have is why will my O2 sensor not take out enough fuel. I can smell that it is in fact running a little rich which would make sense as my O2 sensor is reading low to mid twelves most of the time.. My Aft Corr% is at zero, and my sensor is removing small amounts of fuel, just not enough to bring ther A/F to the targeted A/F (and doesn't swing back and forth). I have even held the throttle open at a constant position to make sure that I am seeing the results of accelleration, and it makes very little difference. My VE tables are not yet perfectly tuned, but the O2 sensor is not taking out the max fuel (or even close to it) that are set forth in the Target A/F Closed Loop Correction Limits..

I have also went through all of the diagnostics set forth in the FAST help section and all of my values are within spec. except for my UEGOS(v) which is 1.04v (the spec. is 1.02v). I believe I asked Tony at FAST about this sometime back and he said that it was ok to be a little high.. Does anyone know if that's true?

I'm new to all of this and am totally stumped on this one. Am I missing something obvious?

 

[norbs]

have you adjusted the a/f correction limits to remove -25% fuel?Please send me some logs i will look at it. I run 83's and my 02 correction is about 2% at idle with a a/f of 14.2 and a large camshaft. It has taken me a long time to get it to run that lean. email me at norbz@sympatico.ca. If it comes worst to worst we may have to do the newtork tuning thing.

 

[norbs]

Where is the o2 located? Why is it getting an artifical reading? Any leaks near the o2 is really going to mess any readings

 

[tonydee64]

Hi Norbs, I was hoping you'd chime in.. The O2 sensor is located right after the header flange of block hugger headers (shorty headers). I guess the part I really don't understand is why doesn't the ECU at least try to correct for what it perceives as a rich condition? It's like the O2 sensor is ignoring the A/F table.

I will run a new log tonight and send it to you. The networking would be neat to try as well.

I appreciate your help.

Tony

 

[norbs]

Can we get a picture of the wb location?

 

[tonydee64]

Norbs was nice enough to let me call him and walk through my problem.. He was a HUGE help. The people on this forum are GREAT!!! I hope someday I can give back to those of you who need help...I lurk here constantly trying to learn from people like Norbs..

Thanks again Norbs!!!!.

 

[norbs]

Thanks Tony, but i am no professional, i just spend alot of time on my fast system, and still dont know alot of things about it. Its just a hobby to me and i do it for enjoyment. Let me know if you get the 02 sorted out any better!