[s-cars] Hard Start, then No start continued........

[Varon H. Fugman]

>> Any BTDT or writeups to give me an idea of what's involved with the FPR?

The FPR is easy.  Just depressurize the system first by breaking a
connection at the fuel filter or firewall first with a rag wrapped around
it.  Once you pull the clip the FPR will come straight up.  It is a snug
fit, so it might take a little persuasion to come out and for the new one to
go in.

>>Also curious as to, if replacing these does not work, if I can test the
Fuel Pump while still in the tank without any special "fuel
metering/pressure" tools or anything?  On every other audi I've owned, the
pump has always made a distinctive noise when pressuring the system upon
startup.

The fuel pump relay isn't engaged by the ECU until after the engine is
cranking and good signals are coming from the crank and cam position
sensors.  If the fuel pressure regulator and the check valve in the pump are
good the system should hold pressure, so the system shouldn't have to
repressurize on startup.

You can manually activate the pump by "injecting" +12V at fuse 17.  If all
is good you'll hear it run.  You can disconnect the fuel supply line at the
driver's side firewall and pump fuel into a can to test flow, but this won't
guarantee the pump is supplying adequate pressure.  If you disconnect the
return line from FPR instead you should also get fuel flow--otherwise the
pump isn't building up enough pressure.  Rig up whatever jumper
wires/switch/helper you need to run the fuel pump for testing--just keep any
sparks as you start/stop the fuel pump well away from any gasoline vapors!!!

>>What is the preferred replacement Fuel Pump for the '95 ur S6?  Looking
for drop in, plug and play.  Only mod is a chipped ECU at the moment.

The VDO is plug-and-play, but I can't recommend it, because mine failed
after 14 months and 11k miles (just out of warranty!)  What's worse, it
failed such that it still made the normal noise, still pumped a good volume
of fuel, but didn't build enough pressure to fire the injectors.  At least
it failed while I was driving up my driveway!

I replaced it with a Bosch pump which required cutting off the original ring
terminals and crimping on spade connectors.  There was no marking as to
correct polarity, and of course with a 50/50 chance I got it wrong.
Evidently the physical orientation of the terminals is opposite the OEM and
VDO pumps.  Rather than dive into the fuel tank again, I swapped the wires
in the wiring harness in the trunk.  It was working fine after 14 months and
17k miles when the car last ran 10 days ago!

Varon
'95 urS6 not starting either

P.S. Found out my wife took the insurance off my S6... :-( I was planning to
fix it tomorrow afternoon!  (Hopefully!)  If I do get it running I guess I
can drive in circles around the driveway. ;-)