V6 no start update - it starts

[SJ]

> From: "Tyson Varosyan" <tigran at tigran.com>
>
> I am familiar with newer engines. Not Audi per say, but still an EFI
ODB1&2
> motors which are, in principal, all the same. To my knowledge, O2's have
> absolutely nothing to do with the car starting. They trim fuel levels for
> optimal burn once the car is warmed up. No O2 sensor I have ever heard of
> will even give a reading until the car has ran for a few minutes. They
must
> be hot and even those with electrical heaters, like the ones on my 3000GT,
> take about 3-4 minutes to start working.

Here is a "What if?".
>From what I recall on the 5 cylinder engines, the computer puts out a
reference 0.5 volt  on the oxygen sensor line when engine is in open loop.
When the computer senses that the oxygen sensor is working (voltage
crossovers at so many per minute) it switches to closed loop.

What if the oxygen sensor is shorted and shorting out the 0.5 volt reference
at the computer?
The oxygen sensor puts out .5 volts at a perfect air fuel mixture
The oxygen sensor puts out over 0.8 volts for a rich mixture.
The oxygen sensor puts out less than 0.1 volts for a lean mixture.
Under the initial start condition, the computer might be sensing the low
voltage(shorted sensor) at the sensor line and leaning out the mixture.

I would disconnect the oxygen sensors, check for that reference voltage with
ignition key on, and try starting with oxygen sensors disconnected.

SJ
85 Dodge PU, D-250, 318, auto
85 Audi 4k - - sold but still on the road
88 Audi 5kq
90 Audi 100q