[s-cars] Found 10 PSI Fuel Pressure and .8 Volts

[Sean Douglas]

Dave:

I bought some used fuel lines from Force 5 and tee'd into the supply
line at the firewall. A rubber fuel line and some adapters and a 0-100
PSI gauge finished off the apparatus.

See picture here, it should be self-explanatory.

http://pictureposter.audiworld.com/52091/fueltester001.jpg

Sean



> -----Original Message-----
> From: Dave Forgie [mailto:forgied at direct.ca] 
> Sent: Sunday, November 06, 2005 9:26 PM
> To: Sean Douglas
> Cc: 'Cody Payne'; s-car-list at audifans.com
> Subject: Re: [s-cars] Found 10 PSI Fuel Pressure and .8 Volts
> 
> 
> Sean:  Can you describe you apparatus for that test?  I 
> remember that you had to get some fittings from Force 5 or 
> Shokan or somewhere. (??)
> 
> Dave F.
> 
> Sean Douglas wrote:
> 
> > Good point Cody, I'm not sure if the injectors running makes a 
> > difference.
> >
> > It would be interesting if you could do the test using the same 
> > methodology as I did to eliminate the variables.
> >
> > Cheers.
> >
> > Sean
> >
> > > -----Original Message-----
> > > From: Cody Payne [mailto:cpayne at bconnected.com]
> > > Sent: Sunday, November 06, 2005 7:59 PM
> > > To: Sean Douglas; Dave Forgie; s-car-list at audifans.com
> > > Subject: RE: [s-cars] Found 10 PSI Fuel Pressure and .8 Volts
> > >
> > >
> > > Hey Sean,
> > >       Thanks for your data.
> > >
> > > At idle w/ vac I am at 62 PSI.  Under WOT around 5200 RPM 
> my boost 
> > > gauge reads around 25 PSI...so I should see 87 PSI on my fuel 
> > > gauge..but only seeing ~70 PSI now vs. ~60 PSI before the 
> new relay.
> > >
> > > So I am still short ~17 PSI.  So really the difference between my 
> > > test, is that my injectors are running high duty as well as the 
> > > loads on the alternator.  I would expect that your expected and 
> > > actual pressures would be slightly different due to those 2 
> > > variables...but I could be wrong?
> > >
> > > Cheers
> > >
> > > cp
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: Sean Douglas [mailto:quattro20v at telus.net]
> > > Sent: Sunday, November 06, 2005 8:41 PM
> > > To: Cody Payne; 'Dave Forgie'; s-car-list at audifans.com
> > > Subject: RE: [s-cars] Found 10 PSI Fuel Pressure and .8 Volts
> > >
> > > Cody:
> > >
> > > When you measured your fuel pressure at WOT, what 
> manifold pressure 
> > > are you seeing? I only ask because the fuel pressure is 
> dependent on 
> > > the manifold pressure and is controlled by the fuel pressure 
> > > regulator.
> > >
> > > I did this last year, but did the test differently. After 
> relaying 
> > > the fuel pump as per Dave Forgie's instructions, I put a pressure 
> > > gauge inline on the supply line, manually jumped the fuel 
> pump so it 
> > > was on (engine off) and disconnected the vacuum / boost 
> line to the 
> > > fuel pressure regulator and pressurized this with regulated 
> > > compressed air. Starting at 0 PSI and going up in various 
> steps to 
> > > 28 PSI, my results
> > > were:
> > >
> > >
> > > 0 PSI, 57 PSI
> > > 10, 65
> > > 15, 70
> > > 20, 75
> > > 22, 77
> > > 25, 79
> > > 28, 83
> > >
> > > By my calculations, I was 4-5% below the target fuel 
> pressure across 
> > > all values. The voltage at the pump was 12.4 volts, 
> perhaps when the 
> > > engine is running, the voltage will go up and hence the fuel 
> > > pressure.
> > >
> > > The reason I did all this testing was because with the 
> RS2 mods, I 
> > > was running lean (pinging) and wanted to see if I had enough fuel 
> > > pressure. In the end I decided it was a software issue 
> and switched 
> > > software (to
> > > Dahlback) and now the pinging is 99% gone.
> > >
> > > Sean Douglas
> > >
> > > > -----Original Message-----
> > > > From: s-car-list-bounces at audifans.com 
> > > > [mailto:s-car-list-bounces at audifans.com] On Behalf Of Cody Payne
> > > > Sent: Sunday, November 06, 2005 6:21 PM
> > > > To: Dave Forgie; s-car-list at audifans.com
> > > > Subject: Re: [s-cars] Found 10 PSI Fuel Pressure and .8 Volts
> > > >
> > > >
> > > > For those who have a fuel pressure gauge on their
> > > cars...what sort of
> > > > pressure have you seen from your stock fuel pump?
> > > > Can you get 86+ PSI WOT?
> > > >
> > > > Granted the set-up I had today was great as I could drive
> > > and view the
> > >
> > > > fuel pressure gauge mounted on the hood.  But on the dyno
> > > works great
> > > > too ;)
> > > >
> > > > My stock fuel pump is about 3 years old.
> > > >
> > > > Thx
> > > >
> > > > cp
> > > >
> > > > -----Original Message-----
> > > > From: s-car-list-bounces at audifans.com 
> > > > [mailto:s-car-list-bounces at audifans.com] On > Behalf Of Dave 
> > > > Forgie
> > > > Sent: Sunday, November 06, 2005 7:10 PM
> > > > To: s-car-list at audifans.com
> > > > Subject: [s-cars] Found 10 PSI Fuel Pressure and .8 Volts
> > > >
> > > > You're welcome Cody.  But at 70 psi you are still down at
> > > least 16 psi
> > >
> > > > from the minimum 86 psi you need at 28 psi relative boost
> > > (58 psi (4
> > > > bar) plus 28 psi boost).  I suspect that your 091G is got a 
> > > > problem -either its weak or its inlet is clogged.
> > > >
> > > > Dave F.
> > > >
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