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Old 09-03-2012, 01:06 AM   #1
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Default Idle adjustment screw won't adjust

I don't remember doing anything ridiculous to it and I did adjust (pretty sure I closed it some to try dropping the idle) it once with no problems, but the last time I went to adjust the idle adjustment screw it would only turn 1/4 of a turn total. After finding it didn't want to go anywhere I decided to go against instinct and beat the **** out of it or pb blast it (those are the only things I can think of to remedy the situation).

Anybody have an idea/recommendation for unfcuking this thing?

This is a 99tb not that, I think, it makes a difference.
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Old 09-04-2012, 05:49 PM   #2
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Anybody?
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Old 09-05-2012, 08:54 AM   #3
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Did you try lubing it?
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Old 09-05-2012, 09:09 AM   #4
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why do you need to turn it?
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Old 09-05-2012, 09:58 AM   #5
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Time for my idle adjustment screw words of wisdom.
Let's say you put a megasquirt or whatever on your car and you eliminated the stock ecu. Now your car idles a little high. What should you do?
Don't touch the f'n idle screw EVER...that's what you should do.
If it idled fine with the stock ecu, then you need to adjust your megasquirt or whatever you're using to make it idle right.
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Old 09-05-2012, 10:02 AM   #6
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exactly.
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Old 09-05-2012, 11:10 AM   #7
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Wish someone had told me that. When I first put in my MS, I messed with the screw. I eventually got it all sorted, but it would have been much easier had I just left the screw alone.

To add to this advice, BEFORE you install the MS, make sure your idle screw is adjusted properly using the FSM procedure. On an old 1.6, that would be to warm up the car, jumper pin 10 of the diagnostic connector to ground, check your timing (set it to stock) and then adjust the screw for 850RPM. Now install the MS and never touch that screw.
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Old 09-05-2012, 11:40 AM   #8
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Failing that, you can use the MS to force the IAC valve to hold a middle position and force 10 deg of timing. Then adjust the CAS till you actually have 10* of timing, and set the idle screw.
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Old 09-05-2012, 11:41 AM   #9
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fwiw, my idle adjustment screw is all the way in...
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Old 09-05-2012, 01:47 PM   #10
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Any words of advice for someone with a 1.6 who removed his IAC AND gave away his stock ecu to fellow miata-er in need?

I royally fucked with my idle air screw ... by removing ... twice

-Zach
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Old 09-05-2012, 01:53 PM   #11
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whats controlling idle now?

i mean the positioning doenst really matter, the range of the iacv is enough to go from 400rpm to 3000rpm.
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Old 09-05-2012, 02:12 PM   #12
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Quote:
Originally Posted by Braineack View Post
whats controlling idle now?

i mean the positioning doenst really matter, the range of the iacv is enough to go from 400rpm to 3000rpm.
Good question ... nothing at the moment aside from adjustment screw (and what ever MS software offers ... which I quite honestly haven't dug into yet). My IAC valve crapped out on me so 'because racecar' I decided to toss it and forget it. The theory being that I don't have AC/power steering (loads) and I only plan on driving the car to autocross events or on balmy summer/fall evenings (weather variability shouldn't be too high).

I did what you're not supposed to do: change everything AND install MS at the same time . I'm concerned I'm not going to be able to isolate variables once it's time for start up.


Side question for Brain - will an auto VPTS work with the MSPNP if the board hasn't been modified? (I'm assuming it plugs into the factory connector ... which it may not)

-Zach
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Old 09-05-2012, 02:14 PM   #13
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no, the auto TB wont plug right in. even then, IIRC, a few jumper wires need to be changed/moved/added in order to run vTPS.

as far as nothing controlling idle, adjusting the screw is exactly the correct solution
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Old 09-05-2012, 02:37 PM   #14
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Quote:
Originally Posted by Braineack View Post
no, the auto TB wont plug right in. even then, IIRC, a few jumper wires need to be changed/moved/added in order to run vTPS.
f*ck ... another task to add to the spreadsheet. Any interest in modifying my MSPNP?

Timeline is not relevant.

-Zach
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