Why am I running rich during PE?

[n8dogg]

You sure that you're running 100% gasoline?? It is common here for stations to water down their gasoline with 5-15% ethanol; also due to Obama EPA laws, ALL pump fuel in the US will be at least 10% ethanol (E10) by 2012, so I would just change the stoich value to 14.17 now IMO. Either way, make sure the fuel you are using matches the stoich value in your tune.

Mr. P.

10% ethanol is in all gasoline around here. :/.

[Taz]

Nice catch Mr. P .... often forget this is a global Forum ... zero ethanol in "premium" gasoline here .... there is 10% ethanol in our "regular" gasoline. I had assumed N8 was running premium gasoline, and that the 14.68:1 setting for stoich was therefore accurate.

I use 14.12:1 for 10% ethanol gasoline. That would loosely equate the PE values to - EQ 1.17 (12.07:1 AFR) and EQ 1.15 (12.28:1 AFR). That is much closer to the WBO readings N8 had observed - 11.9 to 12.2 AFR.

That may explain some of the variance.


Regards,
Taz

[n8dogg]

Nice catch Mr. P .... often forget this is a global Forum ... zero ethanol in "premium" gasoline here .... there is 10% ethanol in our "regular" gasoline. I had assumed N8 was running premium gasoline, and that the 14.68:1 setting for stoich was therefore accurate.

I use 14.12:1 for 10% ethanol gasoline. That would loosely equate the PE values to - EQ 1.17 (12.07:1 AFR) and EQ 1.15 (12.28:1 AFR). That is much closer to the WBO readings N8 had observed - 11.9 to 12.2 AFR.

That may explain some of the variance.


Regards,
Taz

So the stoich setting directly effects PE AFR?

[SSpdDmon]

...also due to Obama EPA laws, ALL pump fuel in the US will be at least 10% ethanol (E10) by 2012....

WTF?!?!? When did this happen???

[Taz]

So the stoich setting directly effects PE AFR?

No matter what AFR you set as stoich, EQ at stoich will always be "1.00". This why tuning in EQ or Lambda (rather than AFR) negates the effect of the ethanol content in the fuel.

If you configured your WBO to produce a result in EQ (directly or via a CALC PID) it should be in good agreement with your commanded PE (EQ of 1.17 to 1.15) - however the corresponding AFR will always be fuel dependent. Again, this why using EQ (or Lambda) output from your WBO will make tuning easier, and more accurate.


Regards,
Taz

[joecar]

Yes, you must set B3601 to the stoich AFR of the fuel you're running.

[n8dogg]

OK this is getting a little confusing for me. I just got back from logging on my lunch break. I changed the B3601 stoich AFR as 14.17. The car ran further rich, I'm guessing based on what you just said Taz, I did this incorrectly. The car also skipped at slow speed parking lot maneuvers afterwards, although its hot as hell outside and the A/C was running and fans blowing.

Here is the latest log with AFR at 14.17:
7-22-2011_AFR ADJ.efi
This is the tune:
Calc.VET_2_14.17.tun
Maybe you can help walk me through the proper way to change the stoich AFR. And what's the answer to the AFR during PE?

[n8dogg]

Here's what I am gathering:

I need to log showing EQ instead of AFR and recalibrate my MAF.
-Is following the Calc.VET tuturial a good way to do this?
-What about the missing FREQ. data in the new map, do I apply the average % to the entire table?

14.17 is stoich for premium gasoline with 10% alcohol, does this require the VE table to be reworked?

[joecar]

Yes, follow Calc.VET tutorial if you're running CLMAF.

The Calc.VET tutorial has info regarding the map.

Changing stoich does not require VE table to be redone. Changing engine's air breathing ability requires VE table to be redone.

[slows10]

You have B3601 set at 14.17 and then B3618 set at 1.17-1.16 . That is 12.11 afr at wot. Thats roughly what the wideband is saying. Why are you using 14.17? What someone is using for fuel in one state does not mean it is correct for you. I wouldnt think B3601 should be changed until it is confirmed by testing thet it is E10.