Re: Gonna start a build and see where it goes ===> TWINSCREW !!! :-p
Posted: Tue Jun 20, 2017 9:44 pm
One of the interesting things about DIY tuning with an aftermarket ECU, is that
there is alway something new to learn. In the last few days I discovered that fuel
injectors have dead times, and these have to be set in the ECU according to the
information provided by the injector manufacturers.
I'm using standard 365cc/min DENSO low-res injectors from a 4AGZE, and since
the interwebz could not come up with dead times for them, I decided to use the
values for DENSO 550cc injectors. Figured the design would be near enough the
same, and certainly closer than the default values in the ECU.
Entered up the new values and fired the engine up. Previously it had been starting
and running fine, but now it stalled out on cold start due to being way too lean.
Driving, all the low rpm/low load points were also very lean, so now I have to start
a whole new tune But according to what I read, having the correct dead times
helps get the best idle quality, and minimise some of the other corrections that
have to be applied to compensate for wrong dead times.
In another week I should have a new fuel map sorted, and be able to start pushing
the engine a bit harder.
Cheers... jondee86
PS: Injector dead times are just how long in milliseconds it takes the injector to
open at different voltages.
there is alway something new to learn. In the last few days I discovered that fuel
injectors have dead times, and these have to be set in the ECU according to the
information provided by the injector manufacturers.
I'm using standard 365cc/min DENSO low-res injectors from a 4AGZE, and since
the interwebz could not come up with dead times for them, I decided to use the
values for DENSO 550cc injectors. Figured the design would be near enough the
same, and certainly closer than the default values in the ECU.
Entered up the new values and fired the engine up. Previously it had been starting
and running fine, but now it stalled out on cold start due to being way too lean.
Driving, all the low rpm/low load points were also very lean, so now I have to start
a whole new tune But according to what I read, having the correct dead times
helps get the best idle quality, and minimise some of the other corrections that
have to be applied to compensate for wrong dead times.
In another week I should have a new fuel map sorted, and be able to start pushing
the engine a bit harder.
Cheers... jondee86
PS: Injector dead times are just how long in milliseconds it takes the injector to
open at different voltages.