I was just curious as to whether adjusting the fuel stabilized table to compensate for some maf transfer error is ok. My maf seems to be dead on from idle to around 3 volts. From 3 volts and up, it seems to run slightly lean. Can I make up for this by increasing my a/f in the fuel table? Does this efficiently work or should I continue to adjust maf?
Maf Transfer off slightly; compensate with fuel stabilized table?
- Thread starter jruppert
- Start date
Yes I am. I had entered 12.5 or so for my wot at high load for a/f and when it came time to driving it was coming out to being around 13.5 or so. I then went back into the table and entered around 11.5 and then finally my wideband showed around 12.1 - 12.5 at wot. Is this ok?
I like to use the greatest load row in that fuel table for WOT use.
I set it fat and the same in all cells.
I then use the part of the maf curve that is never seen in use during Closed Loop to make the value used in the fuel table match the value seen with the wideband.
After this is accomplished ... you can just change the value in that top row for what ever af ratio you desire
Grady
I set it fat and the same in all cells.
I then use the part of the maf curve that is never seen in use during Closed Loop to make the value used in the fuel table match the value seen with the wideband.
After this is accomplished ... you can just change the value in that top row for what ever af ratio you desire
Grady
The Maf is used to determine pulse width at WOT along with the fuel table
I'm excluding any factors that might + or - fuel like the high speed enrichment
function you see in the Cobra.
Say you have your fuel table setup for WOT at 12 to 1
Say you flow 1000kg at 4.5 maf volts for maf point 26
Say you read 11.5 on your wb at that maf voltage
Your too fat at that point
so
You lower the airflow at that point
so
You then will command a lesser pulse width
so
You then will see a leaner display on your next WOT datalog
Make sense
Grady
nevermind.. the maf was screwed up. i loaded up a new one and it went over 4 volts. i did adjust my maf from 3.0 volts to 4.0 volts and was able to get the a/f where i wanted it. i really had to fatten up those numbers. at first i wasnt sure if it was going to work because i was increasing them by so much.
It could be fuel enrichment function
For the j4j1 it starts to come into play at 90 mph
and at 120 for the t4m0
A WORD OF CAUTION HERE
This thread is important!
this area of fuel management is where very little margin of error takes place
and
one could do damage
so
you want to be certain this stuff is understood
If I have not explained myself all that well
or
If anyone has any kind of Q's ... I'm happy to give more specifics if needed
Grady
And another reason I haven't played with that part
I understand
but
No need to be intimidated
When doing stuff you are not sure about
I did tons of it btw
Have a good datalog for a baseline
Make a very small change and only 1 change
Do another dlog exactly the same as the baseline dlog and use the
newest dlog as verification that things work like you suspect they do.
Hard Data
Its your friend
Use it to your advantage
Grady
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