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Discussion Starter · #1 ·
Hi Guys,

Can someone tell me which direction does what for the idle screw?

My screw is all buggered up and I'd like to know for sure which way to turn it since I might not get a second chance.
 

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Why do you want to adjust your idle? What's it at right now?

I'll give you a wall of text to think about

If it's too low or high then there's probably an underlying problem, there's a reason you have developed a low or high idle if the adjustment screw hasn't been touched

First things first, it's a very weak screw. I think it might be plastic, so if you screw it up you're screwed unless you take off the plenum, drill it out and replace it. I'm not exactly sure what's behind it so it may not be replaceable easily.

I'd like to know more about how the vg33 vacuum system works, All I know is it actually indirectly controls idle by opening up the idle air control flow. It allows the idle air control valve to receive more or less air coming from (I think) one of those two vacuum lines that connects to the accordian air duct closest to the filter (don't know which one)

It takes an oversized Phillips bit. Don't try to use a screwdriver, dont try to use an extension. use a bit driver on a small ratchet, just push the pcv hose and throttle cable out of the way with the ratchet. and if you don't have the right size then don't even try - you'll need to go out and buy one

If you've stripped the Phillips slots already, your only hope is a flathead bit. You'll still have two chances, one for each slot of the Phillips head

Press HARD against it, straight, before you start turning

Counter clockwise increases idle air control airflow and clockwise decreases.

I didn't say increases idle because that's an indirect result of increasing the airflow

Because it's an indirect result, you will probably get little to no change. 50rpm change max. Once you have slightly increased the idle, don't keep going because you don't want the screw to come out and nothing will happen anyway

This is only for fine tuning and if you've got more than 50rpm too low or high then this isn't the fix, something else is wrong, and it needs to be fixed, and the fix is NOT to mess with the factory preset throttle blade screw, or clock the TPS sensor (unless the tps is misadjusted or no good which could cause too low of an idle and there is a procedure to check TPS functionality and adjustment)

If you still can't figure it out then worst case scenario you can increase through the throttle cable adjustment (that's not how you're supposed to do it) but you can't decrease because once you slack it the throttle blade will still be held open by its own method so you'll just have a slacked, loose throttle cable with play in the pedal before it starts opening the blade - but your idle will remain the same

Theres not many reasons to touch the screw, unless you feel that the FACTORY idle is too low or high, or how I turned mine up when I put in high lift performance cams because

1. 50rpm higher increased my hot idle oil pressure by 5psi and I want to make sure my top end is getting as much oil as it can at idle, because of the extra stress of performance cams on the top end, and because idling is what slowly kills the top end due to inadequate flow from low oil pump rpm(even though it doesn't need much at idle)

2. I had a slight lope at idle with the high performance cams, the slight increase helped smooth it out

Sent from my XT1080 using Tapatalk
 

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Discussion Starter · #7 ·
You must have a different manual. All I get is this image on EC-31 (last page is 424).




Current idle is about 600. Previous owner told me he fiddled with the idle, and the buggered screw backs that up. I now have the intake fixed and a tune up so its idling smooth. I just need to get the idle back up to normal.

Why do you think its limited to only 50 rpm?
 

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You must have a different manual. All I get is this image on EC-31 (last page is 424).




Current idle is about 600. Previous owner told me he fiddled with the idle, and the buggered screw backs that up. I now have the intake fixed and a tune up so its idling smooth. I just need to get the idle back up to normal.

Why do you think its limited to only 50 rpm?
I think it's only limited to about 50 rpm because that's all I could increase mine to

Your picture looks like a 4 cyl engine I'm talking about the vg33, you might have a broader range of adjustment with the 4cyl

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Discussion Starter · #11 ·
It doesn't matter anyway. I can't get enough of a bite to turn the screw at all.

From what I can see, the only thing left of the plastic screw head is the outer ring.

Someday I will just have to take it apart and see what I can do.
 
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