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L67 Maf tuning help
Posted: Thu Sep 15, 2016 1:42 pm
by ralcool
Hey fellas,
Trying to interpret logging results, still shows some bank differences that even a rebuild and new injectors didn't solve. Hmmm
But I have a more pressing concern. Most of the cells are positive values. This means its ADDING fuel correct?
Therefore its probably running lean at WOT when its ignoring closed loop. iirc. Feels like she's running a bit flat.
But exactly which table needs to be corrected for maf tuning? I just can't find what I need searching.
Here's the log,
to be opened in VS_SC_$51_enhanced.xdf
Thanks heaps.
edit, Here is the bin as it stands.
I thought it was this table, but its all 1.00
Re: L67 Maf tuning help
Posted: Thu Sep 15, 2016 2:10 pm
by Dylan
Fuel trims are based off NB O2. I've read about some earthing problems between banks on the ecotec.
Could be worth a search for a better explenation.
Re: L67 Maf tuning help
Posted: Thu Sep 15, 2016 2:22 pm
by immortality
The VS V6 had the wiring issue with the heated O2 sensors.
The above table (850-1650) is the extended table The1 added so was set to a default of 1.0 as there is no factory info (as it never existed).
Going by the above graphs you need to look at the 50-800 injector rate constant table mostly.
Re: L67 Maf tuning help
Posted: Thu Sep 15, 2016 2:29 pm
by ralcool
I think I've done everything humanly possible to correct the banks. And plenty of searching too.
(Harness mods, linking earths, substitute earths, swapping o2 sensors, different brands NTN vs Bosch plus another oem old set)
Then since, new injectors, both heads rebuilt, all new metal lim gaskets, manifold gaskets... fucken everything.
I suspect it could be flow speed differences in the extractors or something else outside of my control.
But both side are in the positive % zone. That will need fixing. And I'm not sure what table to modify.
A wideband would be the ticket.. but I have to work with what I have for now. No $$ left.
Cheers
Re: L67 Maf tuning help
Posted: Thu Sep 15, 2016 2:32 pm
by ralcool
immortality wrote:The VS V6 had the wiring issue with the heated O2 sensors.
The above table (850-1650) is the extended table The1 added so was set to a default of 1.0 as there is no factory info (as it never existed).
Going by the above graphs you need to look at the 50-800 injector rate constant table mostly.
Makes sense, but the other table is the same too?!
Re: L67 Maf tuning help
Posted: Thu Sep 15, 2016 3:02 pm
by ralcool
By comparison, this is the tables from the VT bins
Top Stock SC V6, Bottom HSV SC V6

- VT_VT_HSV.png (253.05 KiB) Viewed 5989 times
The tuning guides don't talk about maf really.
Re: L67 Maf tuning help
Posted: Thu Sep 15, 2016 3:07 pm
by immortality
Ahh, sorry. VS never had injector rate constant tables so The1 added em.
What sort of exhaust system do you have? Single, twin etc? If it's a twin system does it have a balance pipe?
Re: L67 Maf tuning help
Posted: Sat Sep 17, 2016 11:08 am
by ralcool
The system is something awful made in a proper Geelong workshop.
Pacemakers, to Y pipe into single VN style cat, 2.5" from there into generic muffler and tailpipe.
Loud, drones, no ground clearance.. would be defected on sight. More kinks than a Sydney parade.
Re: L67 Maf tuning help
Posted: Sat Sep 17, 2016 11:26 am
by immortality
Well then it's not the exhaust system.
To tune it you want to adjust the injector constant tables you linked above (that are all currently set to 1.0) I thought The1 had made up a spread sheet where you enter the data from the original injector constant table, add the fuel trim data and it then spits out a new injector constant table?
edit: This is what you want to use
Injector multiplier tuning.xls
Re: L67 Maf tuning help
Posted: Sat Sep 17, 2016 8:29 pm
by The1
have you checked the logs to ensure your o2's are working correctly? You should have plenty of crosscounts on each o2 sensor.