chevy v8 and stepper iac setup

[Dan400]

Hello!
i recently purchased a micro rusefi computer that i plan to use on my 79 monte carlo. currently with a 305 and perhaps latter with a 400ci. i have an old holley throttle body that is tbi style with a dodge iac that interchages with some latter chevy iac up to and including ls style engines. its a stepper motor and this lists as a coming feature on this particular board. i updated the firmware when i setup tuner studios and it appears to be configurable for either multiple pwm outputs or step/direction to be used with a stepper driver (which i have plenty of).

my questions being, is this considered a stable feature? is the git page just not updated? or is the "coming feature" more in reference to using 4 outputs to directly control the motor which im assuming might not be possible on all other hardware because it would require the ability to both pull up and pull down the outputs?

some additional questions, concerns i have. i see no way to pwm control the fuel pump. i do have a regulator and would more like to do this to keep the pump quiet and cool than it being for pressure regulation but it is something i'd like to do, would a registered version of tuner studio help with this?
do the additional feature work with rusefi or are they only compatible with megasquirt firmware?

[AndreyB]

stepper with microRusEFI: at the moment it does not work. in order to move forward I would recomment installing a solenoid idle or electronic throttle body. between low interest and busy developer it's unclear when and how we will have it working. Well, actually now that I am thinkging about it - there is a chance of MRE stepper progress around Sept 20th

fuel pump PWM: at the moment we do not have it. But we have universal GPIO PWM maybe that would work?


I do not get the megasquirt question. rusEFI is not megasquirt and not related in any way, megasquirt has more features rusEFI probably has less in total.

[mck1117]

You can also sort of just ignore idle control - my race car has no idle control to speak of, and has no problem at cold/hot start or cold/hot idle. There's a lot you can do that isn't adding air: for example, add fuel and some timing when cold, and that'll help it idle.

[Dan400]

@AndrewB i was asking about registered versions of tuner studio. is there any advantage to registering or are those features specific to megasquirt?

[mck1117]

@AndrewB i was asking about registered versions of tuner studio. is there any advantage to registering or are those features specific to megasquirt?

there's absolutely value - the biggest thing it gets you is fuel autotune, which we fully support. It also gets you higher datalogging rates, up to around ~220hz on rusefi.

[Dan400]

@mk1117 thank you! perhaps i'll register tuner studio and poke around a bit more.

i may be several to many weeks away from a first startup. i still need some pigtails and only have weekends (weather permitting) to make progress. it looks like i might be able to use another iac in the intended location pn 217-435 that seems to have 3 wires presumably to run 2 directions without an h bridge. unfortunately I can't find reliable information on the application, just a stock image showing 3 pins and a single rock auto ad stating 3 pins. All my searches seem to cross reference it with typical 4 pin iacs which worries me, I ordered one anyway just incase. hopefully a stepper will work soon though.

[Dan400]

got my iac from rock auto that was supposed to have 3 pins. it doesn't. it's genuine acdelco and the part number is correct. acdelco even has it listed wrong on their website as 3 pins so it's not a rock auto error which means the 4 pin cross references are likely correct.