Has anyone else noticed that the AFRMAP numbers logged do not seem to match the values in our current Fuel tables. I was going to try to fine tune the LTFT by changing some columns up or down. However, the values only seemed valid below a TPS of 20%(during decel). That is the only time that that I saw the value change in the logs. I changed all of the 14.7s to 15.1. this should have resulted in the values being 124, but the recorded values were 128

Does anyone have an explanation?? I am beginning to think that closed loop fueling has another undefined table.


HiVoltEVO8

 

Yea I have never noticed them change either, so I just ignore them.

 

I think I read somewhere that it is because the AFR #'s on the current fuel table are only accurate for a stock car. Just use the numbers you log.

 

AFRMAP is the 8 bit number from the fuel table that is currently being used. Do not confuse this with wideband AFR log.

I was actually referring to the logged AFRMAP numbers in Evoscan matching the numbers in the Fuel map in the ECU at a given load. It seems that even if you change the table, the value is still 128.

HiVoltEVO8

 

The value is post lean spool modifications for high loads, and also may be influenced by idle maps we don't yet have. Is the fix at 128 (14.7) you've noted just when it runs closed loop?

 

Ah gotcha, thanks for the clarification.

 

It seems during closed loop, it is ALWAYS 128. However, during decell or accell it seems to go to the value in the table. So it seems that you cannot technically get your fuel trims fine tuned by using the current fuel tables. There is something else influencing the AFRMAP number, like you said. It seems that your only options may be to use the latency and injector scaling number.

The problem that I have is that I can get the trims in at cruising loads, but light accelleration seems to throw them way off.

Hey jcsbanks.....Do you have any of the assembly code. I have been following your work on Aktivematrix and I would like to contribute. I am extremely familiar with Assembly. However, I do not have the tools or experience disassembling the code. I realize that the disassembled code will be huge, but my E-mail account can take it

HiVoltEVO8

 

The fuel tables that we see are open-loop tables. They aren't used for closed loop, that's why changing the numbers in the fuel table won't make any changes at idle, for example.

At cold statup, you will be in open loop for a minute or so though. Look at your AFRMAP numbers then and they should match your fuel table.


Eric

 

So.... if you wanted to tweak a fuel map, and the tweaking was based on a WOT pull (open loop).... you'd use the AFRMAP # to find the correct cell, as opposed to the calculated load?

 

Why wouldn't you just use the calculated load done with the load function instead?