duty cycle drift

[Ameer Antar]

I looked at the Bentley, go to p. 25.28. The spec is 80% w/ a temp sensor 
below 68 degF, meaning in open-loop mode. I'm not sure if cold-running duty 
cycle is s'posed to be the same as WOT DC, but I would assume they'd be 
similar. In any case, it's strange more than one of you is getting only 
65%. Any ideas anyone, Phil?

-ameer

At 06:08 PM 12/4/2000 , you wrote:
>Gee, that's how mine work as well (steady at 65% until warm, whereupon they
>start to control). I'm assured that they're functioning nominally when
>they're "hunting" back and forth. I tried it on 2 different ECUs and
>different cars and it works exactly this way.
>
>Paul Meyers
>Gray 87 5KCSTQ 1.8bar eurolights fuchs 145 kM, needs loom transplant
>Pearl 88 5KCSTQ 1.8bar eurolights fuchs bilsteins 125 kM 2pc-em k24 turbo
>Metallic White 87 5KTQW eurolights bilsteins 191 kM daily driver
>Blue 86 5KCSTQ parts car
>
>
>-----Original Message-----
>From: Konstatntin Bogach [mailto:kbogach at home.com]
>Sent: Saturday, December 02, 2000 7:42 AM
>To: quattro at audifans.com
>Subject: duty cycle drift
>
>
>I was measuring FV duty cycle at different conditions (not driving) and
>found strange drift. At start and cold engine it is stedy 65%. Then it
>slowly moves down and at ~50% it goes to closed loop. Now it changes in
>45-55 range. Bridging contact 2 and 3 on trottle switch connector (WOT)
>send it to steady 62%(open loop). Looks good?
>But after 10-15 min of playing with it I found that at closed loop duty
>cycle is shifting toward 40-50% and stays there. What it might be?
>Something causing rich running?
>
>I did it first time and I have several questions.
>I pressed repeatedly "hold" button on multimeter to see the range of
>duty cycle cause it was changing continuosly on the screen. I saw posted
>messages saying that people observe duty cycle while driving. I doubt
>they used the same method I used. What do they use?
>Another question: using same method I measured O2 sensor output voltage.
>It is between 20mV and 2.2V. From what I read I expected to see ~1V as
>upper value. And I though all of them has same output voltage. Any
>ideas?
>
>Thanks.
>
>Kosntantin Bogach
>200tq 89