Pressure Regulator adjustment?

[Phil Payne]

> Phil Payne mentioned the adjustment screw, but I haven't found one either.

I thought I described the location well enough, but I'll do it another way:

One end has a tiny push-fit hose connection that is usually led either underneath the vehicle
(most
Type 44s, for instance) or into the air mass sensor plenum chamber, above the paddle (Type
85s).  This is a fuel drain intended to prevent underbonnet fires if the diaphragm inside
ruptures.  See Probst for a cut-away drawing, and look below the unit to see where the nice
hot turbo is.  You may find a new hose with a crimp-on hose clip reasuring.

At the other end there is a box-like fitting which serves to collect fuel that is being
recirculated back to the tank.  One of the banjo fittings is on the very end of the unit -
taking it out provides access to the adjustment.

To reach the adjustment, insert a _long_ Allen key all the way down inside the unit.  I've
forgotten the size, but it's a metric half-size - perhaps 3.5mm or 4.5 mm.

Scott Mockry found it, BTW.

I haven't determined what the adjustment does (perhaps Scott now has) but I think it's to do
with residual pressure rather than system pressure.  Its use is not documented, as far as I
know.  I _do_ know that just poking the adjustment has "rescued" at least one unit.  I don't
bother these days because they're so common in junkyards.

> I think he may have meant the pressure accumulator, which is located under the car - that I
believe has an adjustment screw.

No he didn't - the pressure accumulator doesn't have an adjustment screw.  It has a screw on
the end careful - VERY short thread) that's just a plug for diagnostic purposes.  If you get
fuel when you unscrew it, the internal diaphragm has gone west.

--
  Phil Payne
  http://www.isham-research.com/quattro
  +44 7785 302 803