2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

How Do You Adjust AFM?

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Old Jan 14, 2005 | 08:14 PM
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From: King of the road
How Do You Adjust AFM?

How do i adjust my (afm) i think it is? or the (mass air flow Meter). right behind the airbox on my 88 glx there is a screw if turned counter clock wise what will it do to the mixture?
Old Jan 14, 2005 | 08:34 PM
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If it's on the AFM itself, DON'T MESS WITH IT - it's a calibration screw, and you'll most likely mess up how the car runs if you mess with it.

If you're talking about the R - L screw on the strut tower, that's an idle mixture screw that only adjusts air / fuel mixtures at idle.


-Ted
Old Jan 14, 2005 | 08:38 PM
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From: King of the road
No not the idle controll screw. the screw on the afm itsself.
Old Jan 14, 2005 | 08:39 PM
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DON'T TOUCH IT!


-Ted
Old Jan 14, 2005 | 08:39 PM
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I asked what it would do turned counter clock wise..Didnt really ask for you to tell me not to mess with it..I wanted to know What it does to the mixture.. If you have no idea Please Dont reply
Old Jan 14, 2005 | 08:39 PM
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you would probably need the specs to be able to adjust the AFM adjustment screw, i haven't seen the spec for it anywhere or an adjustment procedure so ditto what Ted said ^.
Old Jan 14, 2005 | 08:43 PM
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I vote turn it and let us know what happens.
Old Jan 14, 2005 | 08:44 PM
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From: King of the road
can i get a response from someone that knows anything. or am i gona get the run around. OK so Dont mess with it! ok allready. Now Anyone Knows what the Mixture would change to if the afm screw is adjusted counterclock wise
Old Jan 14, 2005 | 08:44 PM
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if you got a wideband handy and a spare AFM then i say GO FOR IT!
Old Jan 14, 2005 | 08:47 PM
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I am curious, why do you want to change it?
Old Jan 14, 2005 | 08:50 PM
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Ok im gona turn it Exactly 4 turns and ill let you all know what happends...Im bored

Last edited by Adam; Jan 14, 2005 at 08:59 PM.
Old Jan 14, 2005 | 08:53 PM
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all it does is adjust the idle air bleed, past the flapper door.
Old Jan 14, 2005 | 08:53 PM
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I dont know maybe cause i like to fiddle,
Old Jan 14, 2005 | 08:55 PM
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afm reads incoming air? correct? that tells the ECU how much fuel to dump? thats what i have heard
Old Jan 14, 2005 | 08:56 PM
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that's what it does, but if the door closed completely then you would have no air flow, hence the bleed for starting and low idle.
Old Jan 14, 2005 | 09:01 PM
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Since you really want to **** with it, here's the nitty gritty details...

That screw controls a bypass passage around the flapper door.
The MAZDA FACTORY adjusts this once just to get the car running according to their specs.

All it does is increase or descrease a small amount of airflow around the main passage through the AFM.
It will **** your idle up.
It will NOT significantly affect AFM signal at higher RPM's.
The majority of airflow with go through the main passage through the flapper door, since it's opened significantly.

Remember, there is also a fuel pump cut-out switch integrated in the AFM.
If you open that screw too much, too much airflow will bypass the main passage and the door will start to close.
It can close enough to trip this switch, and the fuel pump will keep turning off.
I be the Mazda factory adjusts this switch low enough to be right above the fuel pump cut-out switch trigger threshold.

So, you're just ******* with your idle.
It doesn't affect air / fuel ratio significantly higher than idle.
This is why I recommend not to **** with it.


-Ted
Old Jan 14, 2005 | 09:01 PM
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From: King of the road
so then ya put it back. cant be that hard
Old Jan 14, 2005 | 09:04 PM
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From: King of the road
I have an s4 maybe its the s5's your talkin about,
Old Jan 14, 2005 | 09:10 PM
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so basicly there is no point to take your car into the shop for a tune up..cause you cant really "tune" it cause its allready calibrated? that makes no sence. calibration can over many many years Be off. i can change plugs wires, and all other things myself. So if these things cant be tuned then whats the point
Old Jan 14, 2005 | 09:16 PM
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From: King of the road
Well can you change duty cycle with out a haltech
Old Jan 14, 2005 | 10:40 PM
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Stopbeingapussyandtakethecoveroffandstartadjusting thespringbesuretohaveaspareworkingafmhandybecausey ouwillfuckthelivingdaylightsoutofit.
Old Jan 14, 2005 | 11:24 PM
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Originally Posted by Adam
I have an s4 maybe its the s5's your talkin about,
S4 = flapper
S5 = plunger
I don't think the S5 even has an adjustment screw?
DUH


-Ted
Old Jan 14, 2005 | 11:28 PM
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Originally Posted by Adam
so basicly there is no point to take your car into the shop for a tune up..cause you cant really "tune" it cause its allready calibrated?
You're getting retarded on what you're trying to do.
No, you do NOT take the car into a shop to get the *AIR FLOW METER* adjusted.
You take the car into the shop to get a *TUNE UP*.
Please figure out what the difference is before asking more bad questions.
If you need help on this, don't hesitate to ask.


that makes no sence. calibration can over many many years Be off.
You're right.
The engine wears out.
Parts wear out.
Compression goes down.
Power goes down.
REBUILD THE ENGINE or GET A NEW ENGINE BEFORE ******* WITH THE AFM.


i can change plugs wires, and all other things myself. So if these things cant be tuned then whats the point
So explain to me what does changing spark plugs wires have to do with adjusting the AFM?
Ok, so you replace the spark plug wires when they are worn out.
How about you go to the Mazda dealer to get a brand new AFM for $1,000+ cause your AFM is worn out???
Does that make sense now???



-Ted
Old Jan 15, 2005 | 12:56 AM
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Originally Posted by RETed
You're getting retarded on what you're trying to do.
No, you do NOT take the car into a shop to get the *AIR FLOW METER* adjusted.
You take the car into the shop to get a *TUNE UP*.
Please figure out what the difference is before asking more bad questions.
If you need help on this, don't hesitate to ask.



You're right.
The engine wears out.
Parts wear out.
Compression goes down.
Power goes down.
REBUILD THE ENGINE or GET A NEW ENGINE BEFORE ******* WITH THE AFM.



So explain to me what does changing spark plugs wires have to do with adjusting the AFM?
Ok, so you replace the spark plug wires when they are worn out.
How about you go to the Mazda dealer to get a brand new AFM for $1,000+ cause your AFM is worn out???
Does that make sense now???



-Ted
Because thats what a tune up is, changing plugs wires,timing,(EXT)I would think when you have a tune up they would check air fuel mixture also,. Maybe not who farking know. Im talking about things I can do, verses what i cant do that takes a computer. But im sure you knew what i ment. I may not be Perfectly clear but Come on dont be a ******* ******* too, Im not pretending to know everything because i dont, Just getting the feel for things. I thought a true tune up was CHecking Voltages,specs on sensors,and tps adjustment, and maybe air fuel adjustment, Since Older engines loose compression. Just a thought. what would be wrong with that, Btw RETED or RETRED whatever your name is. Not heard One nice thing come from your Fat mouth, Do you really know anything, Wish i could ignore your ***
Old Jan 15, 2005 | 01:02 AM
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From: King of the road
Also im not talking about Replacing an AFM. Im talking about getting REcalibrated. SHEESH .thats if it even Needs it..agian i dont know.. WHat if they do need to be adjusted. and no one does it. btw 1,000 bucks RIPHOFF. first place i would be is the Junk yard. But i hardly think adjusting the screw is going to Destroy it.



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