Pressure Regulator adjustment?

Phil Payne quattro at
Sun Feb 8 16:07:05 EST 2004

> 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
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
  +44 7785 302 803

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