

| Subject: | Re: AFM adjustment - flap, slider, spring wheel voodoo question |
| From: | Chris S |
| Date: | Sat, 17 Oct 2009 18:18:32 -0400 |
David, thanks for help. I got some sleep, which helped, and took another look at it in the morning. My previous problem was getting the mixture rich enough at high rpm. I had to relax the tension spring to the point that the air flap did not close when engine was off. This morning I turned the wheel just enough to close the air flap and was able to get the mixture close enough to display .6 volts at 3k rpm as 2k and 1k. I was also able to dial in the idle mixture. Not sure what happened yesterday, but I suspect it was a voltage measurement issue on my part. This episode makes want to buy one of those O2 monitor displays, although I shouldn't have do this again for a while. 2009/10/16, David Beierl <dbeierl@attglobal.net>: > Hi Chris -- > > At 06:00 PM 10/16/2009, Chris S wrote: >>http://www.thesamba.com/vw/forum/viewtopic.php?t=356377 >> >>Is this a good way to adjust? > > Mechanical or not, that guy is a good engineer. If you understand > and pay close attention to *all* his advice, including careful > reading of paragraph two, I don't think you'll go *far* wrong. If > his explanations don't make sense to you or if you tend to be a > little slap-dash about things, then I think you're better off not > messing with it. Bosch set these things up at the factory and they > don't expect their characteristics to change during their working life. > > Note well that the method is intended to take an AFM that's out of > adjustment and get it close enough that the feedback from the O2 > sensor can bring the mixture into the range needed for the CAT to > work correctly. How close that is to the original calibration of the > AFM I haven't a clue. > > I think that in terms of killing the engine, the danger is of getting > a mixture that's too lean under some conditions. Dennis Haynes can > tell you lots more about that than I can. > >> What is the actual spring tension function >>vs. the slider tweak? > > Read footnote four again, and then the wiper/spring instructions. If > you still don't understand, pmail me and we'll sort it out. > > >>the above procedure the engine has awakened. I'm still not getting the >>voltage at high RPM the procedure says I should. > > Would you quote the part you're talking about, and what your results are? > > Yrs, > David > > -- Chris S. Disclaimer: "Death and serious injury may occur"
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