Switching on STFT makes car run lean

[stigmundfreud]

Guys

I had gotten my tune pretty sorted whilst in OLMAF but wanted to get STFT taking things over but keep the LTFT turned off. DFCO is disabled still just while logging.

As soon as I enablt stft it goes lean - I've kept ltft turned off and I am not running any custom OS. I'm running 12225074 with a view to going CO3 shortly but for now I'm wanting to understand why turning stft on is shifting things lean? I've set b4206 to enabled

Is it worth altering the switch points and if so any recommendations?

Here is the logs of before and after and also the current tune:

OLMAF: http://www.stigmundfreud.f2s.com/tuning/logs/olmaf.efi

STFT: http://www.stigmundfreud.f2s.com/tuning/logs/stft.efi

tune: http://www.stigmundfreud.f2s.com/tun...at_no-dfco.tun


car: LS1 powered Monaro/GTO

[stigmundfreud]

hmmm 4206 is enabled, default is disabled. Just thinking now about it (as Joe did it seemed on a prior thread!!) that if disabled it shouldnt adjust the commanded just trim to keep close? I'll give that a try.... just when you think you are getting somewhere!!!

[joecar]

Hi Mike,

Interesting... WB indicates lean but STFT's are negative indictaing rich...

What happens if you enable closed loop...?

BTW: regardless, you may want to richen the commanded AFR in the PE table B3618 and posssibly in B3605... 13.6 is too lean for open throttle (high MAP values)... you want something in the range 12.6-13.0... your log shows no knock which is good (you don't hear any...?).

Cheers,
Joe

[stigmundfreud]

never hear nock, I was getting more when I had the cats in but thats more down to the fuck up with how they had to be mounted which pushed me to getting the bypass pipes.

the lean setting in PE was just a tie over from AutoVE and I will be dropping it back (thanks as I'd forgot)

I'm running 3605 with stock hsv settings, 3618 I'm going to set to 13 but the question is why are STFT causing the AFR to read lean? Unless that is my wb setup is wrong. I used the standard LC-1 switch points for analog2 output and did no changes to the LC-1 pid - nor did I run the alalog calibration inside the tune tool - could that account for things being off?

CL triggers are enabled in that I have enabled the temp trigger but turned LTFT off - I suppose I should try with LTFT on as this OS isnt really supposed to run semi-openloop (my understanding). I guess with LTFT turned off the OS doesnt know what to do with the STFT input???

Alternately I could go CO3 but tbh the issues with sorting the custom temp blending put me off.

regards

Mike

[stigmundfreud]

ok enabled LTFT and its still lean according to the WB but I got the multimeter out and have since recalibrated the AD port on the scanner. it shows -0.08 correction so I'm now going to get back out (tomorrow) and start from scratch with autove then olmaf then back to closed loop but before I do that I'll log and see if things match up better

[stigmundfreud]

here is the run down.

1.) Make sure after you have tested the AD input offset. I tested on the bench and all was ok so just assumed there was no signal drop off at the terminal when connected. There's about -0.06v drop off after calibration.

2.) DO NOT PRESS RESET on the LM Programmer, the bastard instructions are not clear and it actually is the same as pressing the recalibration button. Thus my car is now stationary whilst I wait for gas levels to disappear. - DOH

I think the offset of the WB reporting lean and the STFT reporting rich (the new LTFT have improved this difference) was caused by this slight offset for the AD1 input.

Fingers crossed with the lc-1 recal tonight + calibration of the AD port things should start to track true again but of course I now need to redo my autove.

I just hope that was the reason