2 bar OS MAF and VE fueling together

[JonathanLeskewich]

Hi Everyone, some advanced questions here (or maybe they aren't and I just think they are!). I have tuned my MAF table and my VE table. Both were doing quite well (Thanks to help here). After I enabled both together the fueling went a bit lean in the 120 kpa region especially at higher rpm. I raised the Steady State RPM threshold to 6000 rpm and that seemed to help a little.

My questions are: When the MAF is enabled again does it use the 2 bar speed density VE table, or does it cap at 105 kpa even though the OS has been upgraded? If the MAF is disabled does PE work or is that only attached to the MAF, so essentially you then only have VE and BE?

The reason I would like PE and BE both is that I can cross the tables over (tune attached) so that I can run a certain enrichment for boost, but then higher enrichment at a certain RPM with PE.

As well, is there a way to disable the MAF at a given freq./RPM and force into SD at that point instead of just failing the MAF altogether?

If indeed the "together" tune only goes to 105 kpa on the VE table then I will just permanently fail the MAF. I just want to make sure I still have PE then too.. sometimes it's hard to tell exactly what is happening.VE BE PE MAF Final Tune 4.hpt

Thanks,

Jonathan

[kevin87turbot]

The best way to tune yours is SD only. Both PE and BE work nicely in SD mode. The PCM will chose the richer of the two options...either PE or BE.

[JonathanLeskewich]

Ok thanks, I was really hoping someone could confirm that PE worked in SD mode.

So then I just permanently fail the MAF but turn the check engine light off correct?

Jonathan

The best way to tune yours is SD only. Both PE and BE work nicely in SD mode. The PCM will chose the richer of the two options...either PE or BE.

[kevin87turbot]

Yes. Just click MIL on First Error on P0101, 102, and 103 codes...and uncheck the SES.
Also need to change the High Freq fail to 0 Hz.
You'll likely have to alter the P1514 and P0121 airmass tables as well. Most people just max them out.

[JonathanLeskewich]

How well will it compensate for altitude in SD only? I sometimes go from sea level to 10,000 ft in the same day with the motorhome?


QUOTE=kevin87turbot;653940]Yes. Just click MIL on First Error on P0101, 102, and 103 codes...and uncheck the SES.
Also need to change the High Freq fail to 0 Hz.
You'll likely have to alter the P1514 and P0121 airmass tables as well. Most people just max them out.[/QUOTE]

[kevin87turbot]

The stock algorithm on your PCM allows for baro compensation at each startup. After that, the feedback from the O2 sensors allow for fuel trim compensation as needed.