[Prev][Next][Index][Thread]

<MISC> RE: Air Flow Meters

If you have a mechanical Air Flow Meter (with a vane and an embedded 
potentiometer), you can calibrate it. These things are factory calibrated
to a spec, not to the car. Metric Mechanic sells for $5 a procedure to
calibrate one. Don't know how good it is as I haven't gotten it yet (I ordered
it in August, they cashed my check, but no procedure yet :-<).

Basically, to calibrate it, you need to first pry off the plastic cover. After
that, you position the thing such that you can access the springs and
adjustment screws. The O2 sensor is disconnected, and you put a voltmeter on
it. While monitoring the voltage, you first adjust one of the screws (probably
the arm angle offset) to get a .5Volt reading from the O2 sensor. Then, you
increase the engine RPM to a higher setting, and adjust the big round spring
tension adjuster so that the voltage is again .5 Volts. If the Air Flow Meter
is good (ie, all resistors good, carbon track good), you can get it dead on,
and it will now be "calibrated" for your car. 

NOTE! I'm guessing at what the exact procedure is - so don't follow the above
as gospel. 

Generally, older engines tend to run "lean", so you need to richen them with
less spring tension.

Good luck. And, if you are a DIYer, call Metric Mechanics.

David Hoerl
84 633CSi