Calc.VET: correcting MAF and calculating VE (in single log)

[WeathermanShawn]

Len, also make sure you have B0701 set to DISABLE.

Looks like from your Tune you have it set to ENABLE. Could be why you are richer than commanded. CAT PROT takes you to 1.25 EQ.

Also that may be some sort of CAT Efficiency Test. We have to figure this one out. I have never seen an EQ > 1.00 at cruise or decel...

[Dmaxink]

ok so let me get this right (redneck diesel enthusiast here)... The commanded fuel values for this obviously have to be set in EQ Ratio and not AFR. Possibly its posted but maybe i missed it, is there a conversion that can be used to see what the EQ is in comparison to AFR? Im playing with a genIII 5.3 here and this writeup is amazing, very good job.

Also, im not using a wideband, just closed loop with the factory sensors

[WeathermanShawn]

Thanks DMAX:

Joecar has a ton of Links on EQ..so I don't want to butcher his work.

Here is a start on the EQ/Lamda/AFR conversion. A lot of it depends on B3601 in your Tune. I.E. The conversion of EQ is based off stoich..I'm sure Joecar can give you more data. If not I'll get some for you.

For anyone reading along, this relationship has to be understood:

AFR = STOICH_AFR * Lambda = STOICH_AFR / EQR

and, that relationship applies separately in each of commanded and measured contexts;

when you cross contexts you get a correction BEN factor (if you cross correctly):

i.e. BEN is all of these:
BEN = commanded EQR * measured Lambda
BEN = commanded EQR / measured EQR
BEN = measured Lambda / commanded Lambda
BEN = 1 / (measured EQR * commanded Lambda)
. . .
and other combinations using AFR.

The easiest BEN to obtain is the first one listed above.

EDIT: Also check out this calc_pid.txt (look at the last 3 AFR Pids). Joecar breaks down EQ into an AFR conversion..http://forum.efilive.com/showthread....l=1#post140820

[rpmauto]

Shawn, yea our scantools must be set up different. I thought that I had that set to disable,(i dont have cats) but I just looked and you are right. (lots of stuff to remember when starting over from stock.) I will try and get a log tonite and with it set to disable and see what happens. I will post the latest tune from the log last nite.

At any rate in that last log there were only two wot events, one ended up with a ton of wheelspin and the other about 3/4 way through with a long 100% tps then a short one was the ones I was referring to.

Forgot your other question, it is a cable tb. As far as pe coming in early hopefully it is the cat protection parameter. Take a look at the tune and see if you see anything that isnt set right. There are a fair amount of different tables in the 02 os vs. the 98.

[WeathermanShawn]

Thanks Len..your right lots to remember.

I am very curious to know what is causing EQ > 1.00 at various times in your drive. I'm assuming it must be an odd emissions control Table..but nowhere does it display in the Tune. I can't duplicate it my logs..must be a CAT PROT issue...

Well, worst case we can alter the CALC.PE PID to prevent it from contaminating the data..

Yea, you have some wild WOT..7000 Rpm's and some nice VSS's... Notice you hit the max MAF frequency too!

[WeathermanShawn]

Also Len, looking at your Tune..

You do have B3618 set to 1.137 at >6000 Rpms..right?

See the screen-shot shows an EQ of 1.25 being commanded at that point..

[rpmauto]

I have b3618 set up in afr so it is at 12.87 from 2k rpm on. I can set it up in eq, but I understand afr better.

[WeathermanShawn]

I have b3618 set up in afr so it is at 12.87 from 2k rpm on. I can set it up in eq, but I understand afr better.

Your Commanding 11.7 AFR..

Probably CAT PROT..Let's see what happens next log..

[rpmauto]

So the cat protection would drop it that much. I will hopefully get a log tonite. The weather is going to get cold :( and possibly snow a bit here the rest of the week. If not we will have to wait till next week.

[rpmauto]

I got quick log in tonite, I havent had a chance to really look over it yet. I did see quick that the trims are positive at idle, but they are pretty good the rest of the time. (positive during the one wot i looked at quick) selbens are .9 in the upper range, 1.0 for the rest of the maf table. I still get the high spike in the ve table in the 95 kpa row. (not sure how to smooth that one properly yet)

I did notice last year when I was on the 98 operating system when I would let off after a wot run the air fuel would go to like 120, I assume DFCO. I havent noticed that with this. Could some erronous data come from that??

Anyway I will look over the log tonite. Let me know what you think. I would like to track down the discrepency in the difference in air fuel.