Date: Sun, 6 Sep 1998 16:22:06 -0400
Reply-To: Mark Bowie <72142.3566@COMPUSERVE.COM>
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: Mark Bowie <72142.3566@COMPUSERVE.COM>
Subject: Re: AFM Spring Tension
Content-Type: text/plain; charset=ISO-8859-1
Dan-
Thanks for the detailed instructions, I've been unsuccessful in solving the
problem tho. The van still loses power and dies if I try to hold a constant
speed. I'm only able to keep it running if I continuosly vary the engine
speed, tho this is eventually futile as well and I have to shut it off and
restart. I've hooked up a digifant tool, and it all checks out except I'm
unsure about the readings for the AFM and the OXS. I found that I was
unable to keep it running at the 1.5V AFM level Darrell reccommends, I
needed it to be about 2V (measured on the digifant tool) to keep it from
dying at idle, but even then it suffers the loss of power problem. The OXS
reading varies wildly from 0 to 1.2 V.
To date I have replaced the OXS and the temp sensor, installed the
capicitor in the AFM wiring harness, cleaned the AFM contacts, and tried to
adjust the spring tension by your method.
Any ideas what to try next?
MTB
>>hi Mark-
>>sorry for the delay.. busy busy.
>>
>>on an '86, adjusting the afm is quite easy.
>>1. engine off
>>2. disconnect O2 sensor
>>3. remove black cover ontop of afm
>>4. hook a *digital* voltmeter up to single lead of O2 sensor (white),
>>the other two leads off the sensor, black i believe, are for the
>>heater for the sensor.
>>5. screw the adjustment knob in for the mixture (you may have to
>>remove the tamper plug) all the way, then back it out 1.5 turns.
>>6. start the engine, let it warm up.
>>7. notice the voltage from the sensor. ideally, it should flucuate
>>on the high and low side of 0.5v. if it hangs consistently above .5
>>eg 0.8v you are rich. less than .5= lean.
>>8. now push the wiper arm of the afm in either direction. you'll see
>>your voltage reading swing and the engine tone change.
>>9. with your finger or a small screw driver, take the tension off the
>>locking spring wire that engages the black toother gear inside the
>>afm. now you can rotate that black gear to richen or lean out the
>>baseline mixture until you are close to 0.5v average.
>>10. 'fine tune' the mixture lastly with the mixture screw on the afm.
>>11. turn engine off, reconnect the sensor and restart. you should
>>see voltage readings flucuating on either side of the 0.5v.
>>
>>hope this helps!
>>-dan
