4kq bad mileage (still!) (longish)

[Brady Moffatt]

> The one you are looking
> at is a negative temperature coefficient (NTC) switch, in that its
> resistance varies with temerature.  This tells the ECU whether to run
> rich on the cold start "map," in open loop, or to go into closed loop
> and let the OXS signal determine mixture.

Can you adjust CO in open loop? If so, does the computer even bother looking
at it?

> The device should be removed and tested, your Bentley has specs for cold
> and warm resistances - ice water and boiling water make great
> "standards" for immersing it (carefully, boiling water hurts!), although
> they are more extreme than the spec temps.

Yup. In the next day or two, I'll test it.

> > So, where's the "temp sensor (NTC)" that the Bentley shows on 97.270
track
> > 27? It grounds by wire to the intake manifold? It goes to the ECU. My
guess
> > is that's what I'm looking for for my mileage woes.
>
> There are ground wires at
> the intake manifold, two of them I believe, what kind of shape are they
> in?

The ground wires at the intake were clean and tight a couple of months ago.
I'll check them and the ground wire off the sensor again. Is the temp sensor
running a double ground, one through the rad hose flange, and the other by
wire to the intake ground post?

Thanks,
Brady Moffatt
Montreal, Quebec, Canada
86 4ksq, 280,000km
72 Datsun 240Z, 180,000 miles

> --
> Huw Powell
>
> http://www.humanspeakers.com/audi/
>
> http://www.humanthoughts.org/