Fuel tank pressure 200 20V

[Mike Claire]

I wonder if your evap system was just coincidentally doing a self test.
Going by memory, it tests itself every once in a while, when conditions are
right.  As I remember, the tank has to be at least a quarter full, not more
than 3/4, I think the outside temp has to be within some range, etc. etc.
The test is a system pressure check, it pumps the gas tank full of air and
checks for leakdown.  I know this from dealing with a leak on my '01 S8 and
I think (not positive) they existed in '91.

As far as not starting without flooring it, i had that happen to my 9 Avant
2.8, and that turned out to be in intake air temp sensor.

I'm not a "real" mechanic, so take this for what it's worth!



Mike

On Thu, May 3, 2018 at 8:43 AM, Eric Huppert <ehuppert at hvc.rr.com> wrote:

> Last time I took this on a long trip the alternator died and had to spent
> money to get flat bedded home! Three months later I took the same trip
> (with
> doubts) and did make it both ways! Temps were in the low 90's and forgot
> until I tried A/C that I had unhooked compressor for the winter! Argh!
>
>
>
> On the way home (from NYC and heat!) I stopped for coffee for about twenty
> minutes and upon starting car it just cranked. Couldn't hear if fuel pump
> was running as too much highway noise. After  a couple of attempts I
> floored
> pedal and it fired up. Till that point it had been running great. Also ran
> great after that. Proceeded towards home and all was fine! Got home to the
> quiet countryside and turned car off. Immediately noticed a high pitch
> noise
> (sounded like something electrical running). After a moment I unscrewed
> fuel
> cap and "whoosh", noise ceased! Tighten cap and noise resumed!!!!
>
>
>
> Drove this car south last year in heat, no such issues!
>
>
>
> Before I start digging in the Bentleys, any thoughts or BTDT?
>
>
>
> Eric
>
>
>
>
>
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