200q20v Digest, Vol 150, Issue 1

[quikqtr]

Hello Jay, something to check in regards to the fuel tank over pressure concern: would be to check the "Gravity Vent Valve" (roll over valve designed to block off fuel flow to the carbon canister in the event of a "Roll Over"), I  believe the Gravity Vent Valve to be located near the fuel filler neck.
Something compounding fuel vapor pressure in the tank has been the addition of alcohol / ethanol to gasoline and parking in hot weather conditions. 
In regards to the hard start got situation: remember a customer with a mid 80's 5000 that had experienced a loss of power along with a crank / no start situation until he let it sit for a couple hours, he was on a return trip from Las Vegas to San Diego. I was working at Alan Johnson Porsche + Audi at the time, I found a TSB that identified this concern with the addition to Alcohol / Ethanol.The TSB addressed this concern by replacing the Fuel Pump with a Superseded part.I replaced the fuel pump, filter etc... as per the TSB, the Customer reported back after a similar trip with similar ambient temperatures that the trip was trouble free.
I am currently running a Walbro 255 LPH fuel pump in my 200 20V (past 2.5 years without issue).
Later, Randy M.


Sent from my Sprint Samsung Galaxy S8+.
-------- Original message --------From: Jay Kempf <jkempf at madriver.com> Date: 5/3/18  3:06 PM  (GMT-06:00) To: 200q20v at audifans.com Subject: Re: 200q20v Digest, Vol 150, Issue 1 
Last time that happened to me it was because the fuel pressure regulator 
was shot and stuck and the pump was working too hard to counteract and 
that right before it failed internally and started vacuuming fuel into 
the intake making it flood internally. Not fun. But an easy fix and 
actually kinda cheap part.

I suppose a block tank vent system could cause the pump to work too hard 
too. Could be as simple as mud wasps in your vent system. It is a full 
return system so surprised if it was that. Only a few things can cause 
warm start issues if it is fuel delivery: first is check valve at pump 
not closing. Second is fuel pressure regulator not closing. Third could 
be bad injector leaks I suppose. Last is just a leak anywhere either 
internally back to the tank or externally on the ground. Check rest 
pressure to find out. If you can't hold any pressure after shutting down 
then go fishing for leaks or obstructions to flow.

regards,

jfk

802 272 5868


On 5/3/2018 3:00 PM, 200q20v-request at audifans.com wrote:
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Thu, 3 May 2018 08:43:35 -0400
> From: "Eric Huppert" <ehuppert at hvc.rr.com>
> To: <quattro at audifans.com>,	<200q20v at audifans.com>
> Subject: Fuel tank pressure 200 20V
> Message-ID: <4EFFE157E2F0412D9C9D1C3B1049337A at homedesktop>
> Content-Type: text/plain;	charset="us-ascii"
>
> 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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