Re: HELP!!! with Mass Air Flow Sensor (VeeDubClub82)
Reducing AFS Spring Tension
To reduce the spring tension, first remove the black plastic cover on the air flow sensor by cutting up through
the silicone sealer with a sharp blade. You will see, among other things, a black gear-wheel on top of what looks
like a clock spring. A wire clip engages a tooth on the gear-wheel and is held in place by a 7 mm screw.
Scribe a permanent mark on the gear-wheel at the tooth where the wire clip engages (This is so you can go back
to the stock setting if need be).
This is the tricky bit: Get a good grip on the gear wheel with your fingers. Loosen the 7 mm screw and wire clip
assembly. Don't drop anything, and whatever you do, don't let go of that spring, or you may never get the car to
run correctly again!
Now, carefully unwind the gear-wheel 3 teeth counter-clockwise. This is no more than 8 or 9 mm, so be careful.
Reset the wire clip three teeth to the loose side of stock. Tighten down the 7 mm screw, replace the black cover
with a thin bead of silicone sealer and you're done.
I tried one, three, and five teeth... one didn't seem to do much, five actually reduced power. Three was just right.
Stay with three teeth because the down side of too rich a mixture will be increased emissions, and possible
damage to the O2 sensor and/or catalytic converter. YMMV.
I can report that this tweak helps solves some perceived Digifant driveability problems (assuming all else is in
order). Hesitation is reduced, throttle response is crisper, and there is mildly quicker acceleration in the lower
gears due to increased torque. Gas mileage does not appear to suffer much.
Remember, no modifications will succeed if the Digifant system is not in good working order to begin with. In
reality, experience will show that the perceived advantage of possibly expensive modifications will quickly
disappear when you become used to the slight increase in performance afforded by the modification. In other
words, speed is addictive: The faster you go, the faster you'll want to go. The hot rodder's question has always
been "How fast can you afford to go?" - Ken's digifant page...