Quote:
Originally Posted by thambu19
@ arghx7 @ solidONE @ steve99 @ Kodename47 @ ztan
My concern is if the fuel trims go up or down too much say more than 10% it will take the estimated load along with it. Estimated load = Originally assumed load through MAF signal +- corrections from fuel trim. This means the cam and spark lookup will move around unnecessarily?
I dont know how exactly it works on the FA20 so this is just my assumption. This is assuming that most OEMs trust their fuel modeling more than air flow modeling. So when fuel trim moves the load estimation moves as well.
My other concern is how is MAF scaling going to fix this? For example say if by going 100%PFI at low loads causes the LFTF there to go 10% +ve causing a load estimation to go up 10%. The MAF there would be moved up 10% at the same Voltage to bring the LTFT to 0% but we still have the same problem because now the MAF readings are higher (artificially) causing a higher load estimation and hence spark/cam lookup = bad combustion or knock depending on which direction we go in load lookup |
I haven't been able to find exactly where fuel trims get applied, but engine load calculation comes quite close to the beginning and all the trim calculations that I have seen seem to be calculated referencing a figure that has already been finalized. I suspect the trims do get applied to fuelling only and do not affect load.
Changing MAF scale does shift load cell - this should be finalized (or stock values accepted as a reference) first before anything else is touched, as most of the other values reference load. Changing MAF scale later in the process screws around with everything under it in the code.