re. Fuel Distributor Connectors

[Marc Boucher]

Plate rises and falls with slight amount of force.  I've previously measured the resistance across the potentiometer during idle and this confirms that the plate is rising.

There are bolts in the side of the fuel distributor near the top.  When these are pulled, there is gasoline.  I would have guessed that these led to the upper chamber but since there's gasoline there but none coming from the nozzles, these bolts must lead to the lower chamber?

The next scheduled investigations include:
pulling the connections to and from the fuel pressure regulator, confirming that there's flow and trying to gauge if the pressure is high enough (maybe trying to stop the flow with my thumb?)
measuring resistance across diff pressure regulator (its been suggested it should measure 200 ohms at rest )
restarting car to run on cold start valve, with ammeter in line with diff pressure regulator, and measuring current...try to keep car running on cold start valve until it reaches normal operating temperature and seeing if this changes anything...Anyone know if the cold start valve is designed to operate continuously for 20 minutes without burning out? 

I'm hoping that these investigations will tell me whether my next step is to replace
a) fuel pressure regulator (I'd heard there was an adjustment on them but I can't find it)
b) diff pressure regulator
c) fuel distributor and air metering unit


Marc




----- Original Message ----- 
From: Ben Swann 
To: Marc Boucher 
Cc: quattro at audifans.com 
Sent: Monday, February 02, 2004 10:05 AM
Subject: re. Fuel Distributor Connectors


Marc,

When metering plate is lifted, you should have fuel spewing out the top and great gushes of fire hazard.  If not, then something is blocking fuel flow to the injector lines and your trouble is definately in the metering head.  You did a valid test - It may have been safer and saner to pull the injectors, but this did narrow the problem.

Did you experience resistance when air flow plate lifted, or did it rise with a slight amount of force?  

Ben

[Previously, in testing the fuel distributor and metering system I'd done the following:

Disconnect an injector line from the top of the distributor
Lift the air flow plate
Operate the fuel pump

At this point, since no fuel came out from the fuel distributor it was concluded that this was the failure point.

I'm wondering if the bolts that connect the injector lines aren't perhaps a special design that don't permit fuel to flow unless the lines themselves are connected...Does anyone know if this is the case or if this test seems valid?

Incidentally I've tested and there is fuel flowing both from the pump and back to the pump via the return line when the pump is activated.  Has not been pressure tested yet.

Marc]