TMO

I am trying to determine what this table is and how to use it. I have not touched this table thus far as I understand that it is enabled using an option flag. I could not determine which option flag is used to enable this table, so I want to determine if it is being used (the flag is probably obvious). And then understand when it should be used and if I should use it. I did a search but did not find anything. If it out there I apologize for the post. For what it is worth, I am grateful for all the comments from the super tuners. I find it unecessary to post because of the great information.

RBob

iTrader: (1)

That table along with another are used whenever the ECM is in open loop. Once in closed loop the stoich AFR value is used.

The ECM uses the commanded AFR as part of the injector pulse width (PW) calculation. The lower the commanded AFR, the larger the PW.

When in open loop the ECM uses the above mentioned table along with a CTS compensation table to create the commanded AFR.

RBob.

TMO

So the reference in the documentation that says this is enabled via the option word flags is not applicable. That is this table is always used when in open loop? As I said, I have not worked with this table thus far and I am trying to tune my AE. There are numerous posts on that and it appears to be somewhat trial and error. If indeed this table is always used I need to learn how it is used relative to the other paramters. I reduced the AE pulse and it is helping with the 0 to 2000 rpm range, where I have not a bog, just pokey performance. I learned the VE tables using a WB prior to this adjustment and did not see the bathtub shape that would suggest too much AE. Again, most of this is posted and I can review those posts. I have not run accross any posts regarding this table, but I will search again. For now, I simply need confirmation that this table is indeed used at all times in OL and is not enabled/diabled with an option word. That is, it needs to be taken into account and AE tuning is not limited to adjusting pulse widths.

RBob

iTrader: (1)

The AFR table(s) are only used in open loop. However, open loop on a stock tune doesn't last long. Ii will go into closed loop as soon as the engine warms up and the O2 sensor heats up.

The option flags you are referring to force open loop. So when they are used the ECM will go to open loop for that state. And then always use the AFR table when in in open loop.

Note that the AFR table names are preceded by "Open Loop - ". And in the documentation the word "also" is used when mentioning the available open loop modes.

RBob.

TMO

Thanks for your answer and patience. The obvious answer is why I try not to waste folks time. Again, thanks.

nudnig

I would like to resurrect this thread with a quick question. I have the Flash EBL and I was looking at a log I took and found the Commanded AFR was always rich. That is when I found this table. The question. Since I am forcing Open Loop all the time to tune with a WB, wouldn't I want to set this table close to 14.7 across the board? I noticed this table is only at 14.7 in the base tunes I looked at when at a MAP of 70. The rest of the time it is rich. I have attached the graph of the base program and one of what I was thinking about trying. Are there any suggestions for better table entries to try, or if I am looking at this completely wrong?
Thanks,
JT

RBob

iTrader: (1)

One thing to remember is that the MAP KPa is in vacuum, not pressure. With a barometric pressure of 100 KPa, 70 KPa on that table is what we normally see as a 30 KPa MAP reading.

So the closer the 0 KPa of vacuum the higher the engine load. Which is why the stock table values go richer as the vacuum decreases.

No need to set it all to 14.7 to learn via the WB. The commanded AFR is compared to the WB reported AFR for the corrections.

RBob.