Sediment trap (etc.)

[quk@sievers.com (Phil Payne)]

My researches show that the sediment trap was not fitted to the RR (20v)
ur-quattro.

I don't know why.  The tank feeds directly to the fuel pump, then the 
accumulator, then the "fine" filter, and then life gets complicated.
 
The MB schematic clearly shows a sediment trap between the tank and pump, and I 
like the idea, so it's going back on tomorrow.
 
On another subject - I can't find a "theory of operation" for the CIS fuel 
injection system in the form in which it seems to be used in the MB.

There is no vacuum connection to the warm-up regulator (a.k.a. control pressure 
regulator).  There is also no pressure control valve in the metering head - 
just a stub with an O-ring.  My interpretation of the plumbing is that the 
functions of general pressure regulation and WOT enrichment have been combined 
in a single "pressure control valve" or "membrane valve" (German).  This thing 
is bolted to a bracket behind the fuel metering head and seems to be largely
vacuum controlled.

It's linked to the air mass sensor's plenum chamber by an eight-inch small bore 
hose.  When I pulled the mass sensor end, the valve end just dropped off and I 
found it was so badly split as to be almost useless.

Perhaps this is the cause of my full throttle problems.

--
 Phil Payne
 phil@sievers.com
 Committee Member, UK Audi [ur-]quattro Owners Club