Miata Turbo Forum - Boost cars, acquire cats.

- MEGAsquirt (https://www.miataturbo.net/megasquirt-18/)

- - High Idle PWM% Reading (https://www.miataturbo.net/megasquirt-18/high-idle-pwm%25-reading-57548/)

Quote:

Originally Posted by richyvrlimited (Post 724748)

?? No it doesn't. Other peeps are saying by pulling the plug on the IAC revs rise, that implies that the valve is fully open when off which is in direct contradiction to every expensive I've had on a 5. I.e. Everytime you pull the plug on the valve, it closes/turns off/revs drop.

This is on both aftermarket ECUs and stock FWIW

What yourdescribing Pete is the correct operation of the idle valve I.e. It adds supplementary air when required to maintain the idle target.

It does happen on any 1.6 NA, 90-97 (for us europeans)...not on the 1.8 NA though.

1.6L service manual says if you disconnect, idle should go to 1,200RPM.

Ah, not tried it on a 1.6. My mates just bought one tho, time to play...

So to tune the idle bypass crew with absolutely no iac contribution on a 1.6, maybe it's better to physically block off the air hose to the iac valve..? Cos right now I just use warmup mode and just dial it down until I just get the idle valve duty to a step above the minimum value.