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VR 355, '424, 11p

I notice in the tune the maximum motor position for IAC is set at 196.
Is there a reason for this number for a mechanical reason for IAC movement (bottoming out etc).

High comp, big cam, come ttb mani, and I think I'm going to need more than 196steps to get the target idle rpm without touching the throttle pedal.

I previously had the throttle stop in further (showing 1.35v at TPS) and it was causing a lean out stall after a minute which was obviously a tune 'faulty TPS' type mode.
So I'm now back to 1.04v TPS but need more IAC range.

Any work arounds others could suggest?


I see the 'dylan355vs' file from 11p map is at 255 max steps. So maybe 196 is all the stock Holden 'should' need

Zero steps is fully extended (bottomed out in the TB bore) so max steps is the pintle retracted into the stepper motor.

You need to br around 0.5v closed throttle. Doesn't the come manifold have an adjustable bleed on the manifold to add extra air

immortality wrote: ↑Sun Jun 29, 2025 9:02 pm Zero steps is fully extended (bottomed out in the TB bore) so max steps is the pintle retracted into the stepper motor.

Yeah, but is 196 as far as it goes before mechanically max open? If I digitally add more steps to max limit will it be trying to go further and hurt the IAC internally?

delcowizzid wrote: ↑Sun Jun 29, 2025 10:35 pm You need to br around 0.5v closed throttle. Doesn't the come manifold have an adjustable bleed on the manifold to add extra air

It doesn't have a bleed. But I could add one to the emissions vac hose maybe.

You wont damage anything going more steps, but I wouldn't be surprised if it runs out of travel mechanically.

You need to bypass more air so you require less steps.

Can you adjust the TPS at all? Eg move throttle stop further open, and adjust TPS so it's around 0.5v when closed.

pman92 wrote: ↑Mon Jun 30, 2025 6:54 am You wont damage anything going more steps, but I wouldn't be surprised if it runs out of travel mechanically.

You need to bypass more air so you require less steps.

Can you adjust the TPS at all? Eg move throttle stop further open, and adjust TPS so it's around 0.5v when closed.

I loosened the TPS, but could not get any further rotation on it.