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DWS6
May 1st, 2006, 10:58 AM
I have done the auto VE and things in my ve map were clearly out. So I followed the tutorial and was just finishing things up when I noticed when I went back to look at my VE map, the numbers around idle were still 1.02. I checked my STFT and they were -11. I tried adjusting till my STFT got to -4 and then my VE map was 1.04. Seems as though this is backwards. Should I not worry about the STFT at all and just AUTOTUNE VE. Negatives indicate rich and subtracting fuel and anything above 1.00 is lean correct? I did adjust the VE table untill my STFT were -3 and hooked the MAF back up and Calibrated that by logging the values, averaged them in Excell and then pasted back to MAF calibration table, is this correct?

Now the car has a few dead spots in the powerband off idle to 2200 rpm. Not real bad just a small studder, Feels like a hesitation. Everything was fine until I hooked the MAF back up.

Am I supposed to adjust desired airflow, Cracker and Follower tables while in SD or should they only be adjusted after the MAF is hooked up. I adjusted everything and got it running like silk in SD so the only veriable was the MAF sensor but now I can't seem to get rid of the dead spots (kind of like a miss, or a hesitation/studder). Everytime I log the MAF values they get higher I am at like 11.7 at 1875HZ. Also the car wants to keep trying to stall when stopping (surges 2-3 times before finding idle) which I know is in the cracker/follower tables but it was fine SD and before autoVE. Do these tables only get affected when the MAF sensor is hooked up?
Should I readjust to MAF? What does raising the values actually do in the MAF table. Richen the mixture?

Lastly I am afraid to rev to hard or to high while SD with the blower. Is the 15% increase to the VE table enough to compinsate to 11.2 AFR without PE or MAF? The AFR doesn't show to drop below high 12's. Will doing a 30% increase to the VE table change how Autotune works? I would not think it would matter correct.

Any insite you guys could shed on this would greatly be appriciated.
Thanks,
Dave

Doc
May 1st, 2006, 01:43 PM
Fuel Trims? Uh I don't want to sound rude but, I didn't see any mention of a wideband-other than the reference to 1.0 lambda .Tuning by fuel trims is not a very accurate or timely way of dialing in the VE table(s). You have to have all the "adjustments"-Fuel trims, DFCO, etc. turned off and go by your wideband to get the results you are looking for. After the VE tables are +/- .01 then bring the MAF back on line and rescale it with the "adjustments" still turned off with the wideband once again. PM Chad- Black02SS if you don't have a wideband he can set you up.;)

Paging Chad, We have a clean Up on aisle #3

P.s. If you do have a wideband then are you sure about the heater and free air calibrations? Beyond that you could have a ground offset problem.

DWS6
May 1st, 2006, 02:01 PM
I have a WB. (in sig). Heater and free air calibrations? what's this?
When I scale the MAF do I do it while in SD mode? I havent been, maybe that is the problem. How do I log MAF but be sure I stay in SD? When do I dial in the Desired air, cracker, follower tables? Before or after VE?
What is the order of tuning events I should follow?
Should I not even worry about fuel trims so as long my VE map is 1.00 +/- .01
Thanks again,

Doc
May 1st, 2006, 08:13 PM
Whoops, sorry I didn't see the PLX the first time. To scale your MAF, get the VE down pat first. Make a MAP like this. There are more details in the recent threads. Same for idle in gear and P/N if you are auto. If you are unsure of your wideband results then you can log the AD outputs at .5, 2.5, and 5.0v They should track. If they are way off from their respective values I think that would indicate a ground offset problem btw system ground and the heater ground.
Also see
http://forum.efilive.com/showthread.php?t=1891

DWS6
May 2nd, 2006, 12:14 AM
Thanks, for the response.
How do I create the MAP you are showing. I did it a bit different to get actual values to plug in rather then the difference of the values.
Your way seems much easier because you can then see exactly how much and where thing are off. I am not infront of my software at the moment. Could you give me step by step for the BEN for the PLX PID to create this MAP. Also how do I log it, in SD? what do I disable before doing so?
Can you answer the ? above in my last post? Car is an M6.

Thanks for you help.

Doc
May 2nd, 2006, 11:12 AM
http://forum.efilive.com/showthread.php?t=2080&highlight=idle

http://efiforum.iqd.co.nz/showthread.php?t=149

http://forum.efilive.com/showthread.php?t=2227

Search, read, ask more questions

SSpdDmon
May 2nd, 2006, 01:02 PM
I wonder if this has anything to do with the stock O2 switchpoints??? They move the rich/lean threshold for low airflow conditions more towards the lean side, which may explain why your WBO2 said you were fine at idle...but the stockers said you were rich at idle.

Not to hijack the thread...but, anyone else have any thoughts on this? Why would the NBO2 rich/lean threshold be different for a motor consuming 100grams/sec vs a motor consuming 10grams/sec? My LC1 will report a 12.75 AFR (1.8mV) for cruise scenarios just the same as it would when I'm running the 1/4mi. Why should the stockers be any different? Maybe the engineers jig-rigged the NBO2's to provide some sort of "lean idle" or "lean cruise" for low airflow situations??? After all, it's not like you're making huge power sitting still, right?

Thoughts?

DWS6
May 2nd, 2006, 01:26 PM
My desired airflow has been logged and adjusted before VE tuning.
I also adjusted cracker and follower before VE tuning and again while in SD tuning VE. This change did not seem to make any differences. Will cracker and follower work with out MAF?

So is this right?
1. Desired
2. Cracker/follower
3. VE
4. MAF

OR

1. VE
2. MAF
3. Desired
4. Cracker/ follower
Lastly am I logging MAF while in SD? and what do I turn off to do so, so nothing scews the results?

Can anyone comment on the question I asked about the VE table increase?
Can I increase more than the 15% to get down to 11.2 in SD.

DWS6
May 5th, 2006, 08:37 AM
Anyone?