Is this a way of tuning AFM

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Jim Con
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Is this a way of tuning AFM

Post by Jim Con »

I have been having lots of trouble getting my 86 635 to pass smog ( way too rich ).99,000 miles

I am probably going to test the cat next by using a vacuum test to see if it's clogged.

In the meantime I tried this:
Using a DMM I measured the output of the AFM at the output arm at idle (about 1000 RPM) Yes I know it's high

Car warmed up, new O2 sensor hooked up, AFM screw turned out 4 1/2 turns.

Tried to move teeth on AFM, tightening by 1 tooth did make voltage go down about .03 volts.
Decent idle was at about 1.09 volts

Anybody else ever try this, is this a waste of time?

Sorry about coyote pic, couldn't get rid of it!

Thanks,
Jim
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GRNSHRK
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Re: Is this a way of tuning AFM

Post by GRNSHRK »

Jim, got this shot probably from our board, and guessing that it's the same for all AFM's :-k

BTW, nice coyote shot =D>
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Jim Con
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Re: Is this a way of tuning AFM

Post by Jim Con »

Yes , I've seen this great article.

Just wondering if anyone had done this before and approximately what voltage they were seeing at idle on a clean running 635.
This wiil give me an idea of where my "base" point should be.
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tschultz
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Re: Is this a way of tuning AFM

Post by tschultz »

Another article:

http://www.mye28.com/tech/rods_pages/si ... r_wilk.pdf

Unfortunately I don't have voltages for you. However, the O2 and computer should be able to compensate for any differences in AFM besides at idle...

Here was one, but it may be from 528e:
http://www.mye28.com/viewtopic.php?f=3&t=151407
http://www.Drive4Corners.com
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Jim Con
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Re: Is this a way of tuning AFM

Post by Jim Con »

Thanks Tim,

I hadn't seen the 2nd reference where he wrote down the wrote down the segment volt outputs and started at a minimum of .14.
This may be a good starting point.
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Ralph in Socal
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Re: Is this a way of tuning AFM

Post by Ralph in Socal »

Different AFMs have different outputs. Make sure you use the correct information.

Ralph
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Jim Con
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Re: Is this a way of tuning AFM

Post by Jim Con »

I had done the 9v battery test on my friend's great running identical car, his voltage started at .4 at idle and 7.04 volts at full open so I guess there is a substantial difference between years.
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