fuel pressure - CIS

[Ben Swann]

You will have no flow when air flow plate is at the rest position even when the fuel pump is jumpered on.  You will have massive flow when the plate is lifted.  You can lift the plate without removing the waflle boot by taking a 3mm allen wrench and inserting into the air/fuel adjustment screw on the metering plate, then lift without turning the screw.  Sometimes access to the screw is blocked by a plug installed by the factory and must be drilled out.  Alternatively lift the plate by removing the filter cover and reaching under and pushing up on the plate.

You should not even have to remove the injectors from the lines to test injector spray and pattern, as when the pump is running a nice conical pattern should emerge from all injectors as the plate is lifted higher.

If you have no injector spray/fuel flow to the lines, then you have a blockage somewhere in the metering system, perhaps control pressure too high or system pressure regulator blockage.  Study what is going on carefully prior to disassembling any of the metering head.  Very rarely is a problem in the metering head itself.

Refer to Bently for more information on the fuel distributor and injection in general.

HTH..Ben

[Date: Sat, 17 Jul 2004 09:57:55 -0500
From: Jim & Michelle <jimhill at blomand.net>
Subject: fuel pressure
To: quattro at audifans.com
Message-ID: <000c01c46c0e$71dd7fa0$329690cf at jim-s>
Content-Type: text/plain; charset="iso-8859-1"

If I disconnect the injector lines at the fuel distributor and started the fuel pump should I have fuel squirting everywhere?  I have have pressure at the filter and lines going into the fuel distributor etc.  but not at the injector lines.

Thanks
88 5KT]