IAC hissing

[nes138]

got her in finally and warmed up. The IAC hisses something fierce. This video was taken when it was warm and it was still hissing (or is it sucking?) slightly. I did some quick research and didn’t come up with much.
Engine bay is not finished
https://photos.app.goo.gl/iGLgvE3yhAviK3WX7

 

[delcowizzid]

The hissing is normal when the iac steps are nice and low and controlling idle more noticeable when you have a pod too.the mad that close to the tb probably isn't good or the pod both would of thrown the mad calibration out a lot

 

[nes138]

The hissing is normal when the iac steps are nice and low and controlling idle more noticeable when you have a pod too.the mad that close to the tb probably isn't good or the pod both would of thrown the mad calibration out a lot

You mean MAF sensor? It's too close? Goddammit, I shoe horned the dam thing in as it was.

 

[Immortality]

You could try adjusting the TB butterfly a touch with stop screw and see what it does. I know on our V6 if it's adjusted just right it sounds like the serpentine belt is fucked and squeeks. I actually took a die grinder to the TB IAC passages and knocked off a the square edge inside to try and reduce the whistling, it reduced it a bit but didn't eliminate it.

 

[afstruct]

No help with your problem
but this needs a ride thread with plenty of info and heaps of photos as this is one fantastic looking and interesting ride.

 

[nes138]

No help with your problem
but this needs a ride thread with plenty of info and heaps of photos as this is one fantastic looking and interesting ride.

You mean this one???? https://forums.justcommodores.com.au/threads/nes138-room-for-improvement.225896/page-3
Or do you have time to go over 40 pages of stuff?? http://forum.fefcholden.club/index.php?topic=21578.760

Haven't updated in quite some time and haven't done much as I am moving round the country a lot with Defence.



I am interested to know about the closeness of the MAF and the F@%king whistling that doesn't seem to go.

 

[Nut Kracker]

I'd say it's a combination of the maf and the pod filter being in such close proximity to each other and to the T/B.
Pod filters are notorious for that sucking noise.
Options I'd consider, is to have a mafless tune done.
Or try and lengthen the intake ducting.
But buy the looks of it, there's not much room in there.

 

[nes138]

.......Options I'd consider, is to have a mafless tune done.
Or try and lengthen the intake ducting.
But buy the looks of it, there's not much room in there.

I assume I can't get a MAFless tune VATS removed chip off the shelf either

 

[EYY]

Maf won’t like being that close to the throttle blade. They seem to like about 150mm of straight pipe before and after the maf to work properly (notice how the pipe protrudes into a stock Airbox on a maf equipped Holden).

You can change to a VR or VS 304 map based system if you really wanted to do away with the MAF. This is the easiest way.

I believe electronic automotive were the only ones to do the mafless setup for the roller cam engine management system which used kalmaker from memory which is well outdated now, although it works. A mafless tune isn’t an economically viable option these days for a roller cam 304.

As for tuning the memcal based Delco pcm’s, there are plenty of people around who can help tune. You never want an off the shelf tune anyway tbh. Mail order tunes are usually around the $150-200 mark.

 

[nes138]

Godammit... Why aren't cars easier! Think I'll jam it through the bay wall to the wheel well then, At least I'll have cold air induction then. Just have to work out how to avoid getting water in it