pcmhacking.net

have a read of the FAQ button top right of your screen next to logout.

Read these two
Q. What are the differences between short term fuel time STFT and long term fuel trim LTFT on MAP and MAF cars?
Q. What are BLMs?

Basicly the MAF meter is an automatic fuel injector adjustment device, if it meters more air it will add more fuel, less air less fuel, pretty simple, it also meters for adjustment in elevation, humidity etc etc so it is pretty accurate.

Now the issue is we are also trying to achieve a target Air Fuel Ratio, so we need to dial in adjustments to bring it back on target as this is not the MAF's job, now after you read those 2 questions you can then use the two history tables(Inj Multi LHLT% & Inj Multi RHLT%) after playing a recording back to adjust your inj mulitiplier table by the % shown in the history tables. Also select Averages from the dropdown. Note this is only adjusting normal driving in closed loop, to adjust for WOT & Lean cruise you will need a wideband and use the WB AFR Vs Commanded AFR Multiplier History Table also assuming you have adjusted Lean Cruise targets and WOT Targets correctly.

Hi, i have been tuning with $12p in the past MAP system
I want to know more with this Maf system and how to calibrate fuel with the Inj Multi LHLT% & Inj Multi RHLT in excel spread sheet

im by no means an expert on MAF's but i'd suggest getting a wideband sensor, make a value in the adx which will use the wideband and target afr to workout a difference percentage, and plot that in a histrogram against maf hz (or whatever the maf scale in the xdf) then use that to offset the maf tables.

theres probably spreadsheets for that stuff out there, weather they use fuel trims or wideband etc to get the result its probably much of a muchness aslong as your narrowband is accurate (ie. not too old)

yep. general theory: use the above info to calculate the error % and adjust maf hz tables to apply the correction.

Hi I think i am not asking the right question here
On the first page of this thread there is a excel spread sheet "THE1" has posted
its used to help calibrate fuel using Wb and Inj Multi LHLT% & Inj Multi RHLT using histrograms
I would like to know what to cut and where to paste into excel to get new figures to
paste back to bin file
Thanks

stevedarman wrote:Hi I think i am not asking the right question here
On the first page of this thread there is a excel spread sheet "THE1" has posted
its used to help calibrate fuel using Wb and Inj Multi LHLT% & Inj Multi RHLT using histrograms
I would like to know what to cut and where to paste into excel to get new figures to
paste back to bin file
Thanks

The posts i have just made should be all you need to do, however there is always multiple ways to skin a cat, you can use the spreadsheet to change the "Flow to Hz" calibration for the MAF but largely should be unneeded now with enhanced mod adding in the extra inj multiplier tables. To use the spreadsheet you put the logged %'s in the adjustment column of the spreadsheet then change the maf tables to match, though this is a much more slow and cumbersome way of tuning fueling.

have added in injector multiplier tuning xls sheet on the first post.

Thanks The 1, I get it now.
I was confusing the injector multiplier with Maf, I will use the injector multiplier to tune .
Just to confirm in tuner pro it is the "injector Rate Constant Vs mg/cyl Vs RPM" table i am adjusting

yeh correct.

There are many ways to tune fueling, even alot of profesionals tune via the maf tables mainly because there is no injector tuning tables, the maf on commodores seems to have a very fine adjustment more than 10% adjustment in areas tends to do weird stuff, have never had time to check it out fully.

Thats great This makes it easy
thanks again for all your help