eraser

iTrader: (2)

So I just finished up installing my MS-1 I purchased from another member here, did the MAF deletion and all that stuff. Now I have this ( for lack of a better term) hum coming from my intake. Its loud enough that is hurts your ears and occurs at idle the loudest but dissipates the hight the RPMs are. I did figure out it is coming from the Idle air control unit and is magnified by the intake pipe ( Old school Rspeed intake). I am running the base map provided on the DIYautotune site until this weekend when I have a chance to actually do a bit of adjusting on the Dyno. had anyone ever experienced this before and is there a fix? BTW its a 1994 1.8 with header, intake and full exhaust. I am running tunerstudio if that matters.

18psi

iTrader: (76)

adjust idle stepper motor frequency

eraser

iTrader: (2)

I tried that and it didn't seem to help much, I guess I will dick around with it tomorrow when its not so late. Any other ideas?

kotomile

iTrader: (24)

Make sure your intake hardware is tight and not buzzing against anything.

eraser

iTrader: (2)

That was the first thing I check was all the hardware and misc stuff I had fiddled with. I am 100% sure its the IAC valve, I actually pulled it from the intake pipe and the sound became much more bearable ( intake was acting like a megaphone), but the noise is still present.

Reverant

iTrader: (10)

Some buzzing is normal, I even had that with the stock ECU. To get it as low as possible, you need to run the valve at a frequency of 500Hz, using Jean's PWM multiplier board.

Dimitris

WestfieldMX5

I believe the NA has a slightly lower frequency than the NB, just under 400Hz IIRC.

eraser

iTrader: (2)

Got it fixed, kept playing with the frequency utility it went away, now it just idles high. Lol

mgeoffriau

iTrader: (7)

Dammit, had a smartass response all ready to go when I clicked on the thread and you've already fixed it.

eraser

iTrader: (2)

Glad I beat ya to it