Quote:
Originally Posted by Kodename47
Thanks guys, I think I'm getting my head round it. Questions:
I have not changed injectors, so is there any need to do full PI/DI sweeps? From this I can just run full open loop to dial in the MAF, correct?
Injector latency, again no need to be concerned? How do you calculate that?
Changing PI/DI ratio will have an affect on AFRs? If I do this with no injector change, is can this be overcome by pure MAF scaling?
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if you've never changed injectors then you have the luxury of using them as your known quantity to scale the maf and di. in this case you'd scale the maf against the injectors in port only mode, then switch to di only and scale the di against the now-known-good maf. of course stock injector calibration leaves something to be desired, so you can go back in port only and tune the latency and scaler later if necessary.
similarly you could scale the maf using only combined logs, as both the di and ports are known to be at least as good as stock (because they are still stock lol).
injector latency issues will show up in fueling error charts as larger error at low maf voltage (corresponding to low injector pulse width) with smaller error as the voltage (and ipw) goes up. you can see my screencast on generating fueling error charts for a slightly more in depth explanation (though not much
).
again none of this is the gospel. it's just one man's way of accomplishing low fueling error with two fuel systems.