CIS help?

[Huw Powell]

> Having problem with CIS I followd Orin's advise and tried to adjust
> air/fuel mixture so the measured OXS output voltage, while it is
> disconnected from ECU, is ~0.5V.  I could not do it.  Voltage jumping
> all over the place. I can get to the point - makig it richer - where
> voltage stay stable at ~.87V.  Slowly making it  leaner gradualy(but
> very small change in the screw position) reaches ~.75V and then goes
> to the state where voltage randomly jumps betwee 0.004V to .9V.
> Going far to lean makes voltage stay at ~.001V.

that "hovering" point where it keeps flipping back and forth is the 
closest you are going to get.  Leave it there.

> Does OXS voltage should stay more less at same level in whole voltage
> range while signal wire is disconnected from ECU? I think it should.

It won't.  The OXS is too sensitive for that, the tiniest bit richer or 
leaner will peg it one way or the other.  In actual operation it never 
sits in the middle, it swings back and forth over its middle range while 
the ECU constantly adjusts mixture to keep it there - very close to stoich.

With the OXS disconnected, even at the "perfect" adjustment point, I 
would the exhaust is probably still slightly inconsistent from moment to 
moment, resulting in the random jumping you see when you are that close.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/