Weird lean issue after fixing IAC

[1992-25th]

02 Camaro, LS6, M6, Fast 92/92TB, fast 36#, LT's, CAI, unknown cam.

The car originally came in and was rich throughout the entire tune, usually had high 13 AFR's at idle and into the 11's in cruise and WOT. The car came in with the tune locked into OL, both o2's were dead and not switching like they should. the car also idled way above commanded and would "hang" at both idle and coming down out of gear.

I figured out the idle hang issue, I put a new IAC in and did a relearn, well the throttle blade was cracked open to far (.75v on the TPS) so the iac was not working at all at idle, closed the throttle blade to .59v and did a relearn and that solved the idle hang issue, it also solved the high idle issue I was having.

my problem now is that the car wants to die when you try and start moving, as soon as you try to let out the clutch and put load on the motor it pulls it right down and it wants to die, then after every gear change its wanting to do it also, I cant get the car to read steady afr's at all, I am getting 13's at idle but as I try and drive the car they hang in the 12's through first and shoot to full lean and then slowly taper down to 14's in other gears, most of the time AFR's want to hang in the 16-17's. I added 15% to the MAF and VE just to try and it didn't seem to help.

as a test I disabled the MAF and put it in SD and the AFR's are back rich all the time, high 12 - low 13's at idle and into the 11's and 10's at cruise with no spike in the AFR's on the shifts. then as a test I re-enabled the MAF and set the hi/lo RPM thresh to 0 so it will only watch the MAF and the car goes right back to really lean AFR's at cruise like the logs posted. I did not change the VE or the MAF tables at all from the stock tune so I am mystified why the AFR's would be so much leaner, only change was swapping the IAC,doing a relearn and swapping o2's.



The tune that is in the car now is attached, along with two logs showing the issue, the second log (afr issue 2) had a different config loaded so it shows some more info.

[1992-25th]

No ideas on where to start?

[artiechubb2]

Fuel Pressure ?

[Mudweizer]

Is it possible to check the TPS voltage with the scanner?

[1992-25th]

I have TPS voltage logging in the chart and it seems to be accurate, as in it follows what the pedal does on shift.

[fullthrottle]

Jason 02 sensors.PNGgood switching o2 sensors.PNG

Where did you get your fuel injector Data? and your O2 sensors are not switching. That is a problem. start by fixing that.

in the first pic ABOVE, is your 02 sensors, the second pic is an example of what they should look like when they are switching properly.

[1992-25th]

Injector data is what was in the tune from the last tuner, we are doing some other work on the car and the owner asked us if we could look at the tune.

Both 02's are new, I replaced them when the car came in because one was flatlined at 400mv all the time, I can't seem to get them to want to switch correctly

[02statesman]

Both 02's are new, I replaced them when the car came in because one was flatlined at 400mv all the time, I can't seem to get them to want to switch correctly

That's because you're in open loop... they're not switching at all. They're just following how lean or rich you are... which is mostly rich.

[gagliano7]

Your closed loop enable temp in fuel>open closed loop> ect vs iat is set to 280 degrees so you are always in open loop.

[FBODYMAC]

Just so I am clear, when in Closed loop there will be no switching by the o2 sensors because they aren't used yet right? I'm having similar issues and I disabled closed loop for tuning purposes.

[1992-25th]

Just the opposite, when in open loop the computer does NOT look at the o2's, when it goes closed loop then it looks at the o2's. I am not having any switching when in CL either, when I enable CL I get one o2 going full rich and one going full lean. I just swapped wires around to see if they had them backwards when the customer installed the motor.

[1992-25th]

Ok, just got done swapping the o2'2 harness and put it back in closed loop and they are now cycling like they should, car still has that lean spot right after you let out the clutch and it running lean pretty much all the time.

here is the log I just took