MAF(Limit) E2VG212E, help needed.

crippsdr · **Posted:** Mon Apr 15, 2013 2:52 am

Hey eveyone been having problems with MAF limit on my ECU, any help defining whats going on would be great.
I am unable to fuel up properly when injector scaling set to 550cc (when in boost/over the MAF limit???)
Only way i can find to over come this is to set the injectors to 200cc and rescale all the load values.
Would rather be able to set the injectors to the correct scaling, as it idles, starts and runs smoother this way...
Previous talk can be found on this link.
http://www.romraider.com/forum/viewtopic.php?f=15&t=8985
Page 4 has some graphs explaining whats going on with MAF values.

Thanks in advance.

PS. Im happy to give someone a few dollars if they sort this issue out.

td-d · **Posted:** Mon Apr 15, 2013 10:00 am

I believe I've found it. Check out this table:

Code:

ROM:0007EB88 Table_EngineLoad_MAX?:.data.w h'11      ; DATA XREF: Func_Test_MAF_limits+144o
ROM:0007EB88                                         ; Func_Test_MAF_limits:off_20E68o
ROM:0007EB8A                 .data.w h'800
ROM:0007EB8C                 .data.l flt_C1B20
ROM:0007EB90                 .data.l word_C1B64      ; = 9.7e-1
ROM:0007EB94                 .float 0.000061035156
ROM:0007EB98                 .float 0.0

The values are engine load maximum figures (against an ECT axis) - and they correlate to your logs, which max out at 1.2 load. Further in the routine, 0.2 load is subtracted from the calculated load figure - which gives you 1.2 at normal engine temperature. The scaling is also consistent with engine load.

These are the values in the table:

Code:

ROM:000C1B64 word_C1B64:     .data.w h'3E14          ; DATA XREF: ROM:0007EB90o
ROM:000C1B64                                         ; = 9.7e-1
ROM:000C1B66                 .data.w h'3E66          ; = 9.75e-1
ROM:000C1B68                 .data.w h'3F0A          ; = 9.85e-1
ROM:000C1B6A                 .data.w h'40A4          ; = 1.01
ROM:000C1B6C                 .data.w h'428F          ; = 1.04
ROM:000C1B6E                 .data.w h'4333          ; = 1.05
ROM:000C1B70                 .data.w h'4385          ; = 1.055
ROM:000C1B72                 .data.w h'4666          ; = 1.1
ROM:000C1B74                 .data.w h'4666          ; = 1.1
ROM:000C1B76                 .data.w h'4A8F          ; = 1.165
ROM:000C1B78                 .data.w h'4A8F          ; = 1.165
ROM:000C1B7A                 .data.w h'4D71          ; = 1.21
ROM:000C1B7C                 .data.w h'599A          ; = 1.4
ROM:000C1B7E                 .data.w h'599A          ; = 1.4
ROM:000C1B80                 .data.w h'599A          ; = 1.4
ROM:000C1B82                 .data.w h'599A          ; = 1.4
ROM:000C1B84                 .data.w h'599A          ; = 1.4

Bump up the thresholds, and see if that works.

crippsdr · **Posted:** Mon Apr 15, 2013 10:56 am

ok bumped everything up by 3x.
It looks to me as if the Values are engine speed to Engine load. When i use ECT is comes up with weird values but engine speed is fine (ie, 600,800,1000,1200,1600,2000,2400,2800,3200,3600,4000,4500,5000,5500,6000,6800).

anyway ill try that.
Thanks

td-d · **Posted:** Mon Apr 15, 2013 10:58 am

crippsdr wrote:

ok bumped everything up by 3x.
It looks to me as if the Values are engine speed to Engine load. When i use ECT is comes up with weird values but engine speed is fine (ie, 600,800,1000,1200,1600,2000,2400,2800,3200,3600,4000,4500,5000,5500,6000,6800).

anyway ill try that.
Thanks

You need to work on your scaling

It's a 2D table, not 3d - i.e. only an X axis with ECT.

crippsdr · **Posted:** Mon Apr 15, 2013 11:03 am

Sorry can you show me??

td-d · **Posted:** Mon Apr 15, 2013 11:07 am

Apologies, I meant to say RPM axis :oops:

td-d · **Posted:** Mon Apr 15, 2013 11:08 am

No problem, give me a minute.

td-d · **Posted:** Mon Apr 15, 2013 11:11 am

Here you go:

crippsdr · **Posted:** Mon Apr 15, 2013 11:16 am

Yeah thanks, whats what i was meaning anyways. Ill give that a go in the morning.

td-d · **Posted:** Mon Apr 15, 2013 11:18 am

Looking at your logs, I'm positive this is the table.

crippsdr · **Posted:** Mon Apr 15, 2013 11:27 am

Yeah how the load changes between 2400 and 2800 also 3200 and 3600..

crippsdr · **Posted:** Tue Apr 16, 2013 2:03 am

Pretty sure that has fixed it!!

crippsdr · **Posted:** Tue Apr 16, 2013 2:17 am

td-d wrote:

I've been trawling around the MAF compensation logic, man there is a lot of manipulation of the mass airflow input.

I think I may have found a limit - however, it's set at 300 - so seems odd that it would be restrictive.

In any case, try this:

Code:

ROM:00025D60 flt_25D60: .float 300.0

Do you rekon this is correct for MAF limit?? Im getting up to 270g/s atm, putting a bigger turbo on soon, so want to bump it up.

Thanks td-d!!

throttlehappy · **Posted:** Tue Apr 16, 2013 2:27 am

This explains Bryan's car limit as well Cripps!

crippsdr · **Posted:** Tue Apr 16, 2013 2:44 am

throttlehappy wrote:

This explains Bryan's car limit as well Cripps!

Yeah thats it!! Was looking at one of his Dyno graphs and the afr's were bit funky.
Can sort that out now.

RomRaider

MAF(Limit) E2VG212E, help needed.

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