Control Pressure Problem

[housecall55 at yahoo.com (Cris Carpenter)]

CIS-E and plain CIS are not the same, and an 81 will have only one fuel pump. If the control pressures are indeed as high as the system pressure, something is blocking the return through the control loop. Are you simply substituting one bad WUR for another? If the control pressures are that high, it should have a real hard time running at all, but especially cold. If you are sure you are using a known good WUR, the problem must be the fuel distributor. The control loop uses some fuel pressure to hold the fuel distributor plunger down. The air flap of the fuel distributor has to overcome the control pressure to raise the piston and let more fuel to the injectors. The control pressure is lower when cold by virtue of the WUR bleeding it off through the return circuit back to the tank, allowing the piston to ride higher and let more fuel to the injectors until the engine starts to warm up. But both the feed and return side of the warm-up loop on an 81 goes through the fuel
 distributor. If you are acccurately testing the control pressures (I've seen people set it up wrong), have tried a known good WUR, and you still have control pressures that high, the problem must be the fuel distributor. 
   
  Cris
   
  Message: 8
Date: Sun, 3 Jun 2007 10:04:29 -0500
From: "Don Walter" <dswalterwi@xxxxxxxxx>
Subject: Re: Control Pressure Problem
To: "Gordy Stedman" <ydrogs@xxxxxxxxx>
Cc: Scirocco-l@xxxxxxxxxxxx
Message-ID:
 <6155f0910706030804q597c74c5t49e7fae958e7dd2e@xxxxxxxxxxxxxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

What pressures are you expecting?  Is the plate in the fuel distributor
moving freely?  It might be the pump it self on top the distributor.  I 
have
a brand new one of those sitting here that cost me $300 new from a 
CIS-E,
not sure if that would would for your CIS.  It would sell it for half 
that.


How are your fuel pumps, both of them?

Enjoying CyberCincy!


On 6/2/07, Gordy Stedman <ydrogs@xxxxxxxxx> wrote:
>
> So I hope there is enough of us not in Cincy to help Sean and I out.  
Our
> 81 project is having some CIS control pressure problems.  The control
> pressure is the same as system pressure at all temps, about 4.9 bar.  
We
> changed the warm up regulator with another one with no effect.  We 
blew
> compressed air through the return line and it was moving freely into 
the
> tank.  The 2 fuel lines from the fuel distributor to the WUR were 
blown
> out
> also.  There are no leaks that we could find in the fuel system.  The
> screen
> on the WUR was clear of debris and installed new fuel filter.  Anyone 
have
> some input?
>
> --
> Gordy
> MK1 x 5
> _______________________________________________
> Scirocco-l mailing list
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>



-- 
Don Walter - Waukesha, WI
1986 8V Black Scirocco (Daily Driver)
1984 8V Audi 4000s (RIP 2/14/2006)
1986 2.0L 16V TEC 2 Black Scirocco (see progress at
http://www.cardomain.com/memberpage/708939)
1986 2L 16V Toronado Red Scirocco (Ben's Car)
1988 1.8 16V Toronado Red Scirocco (sold on 3/29/04)
1984 1.8 8V Pewter Scirocco (sold years ago)
1971 Karman Ghia (sold)
1969 Karman Ghia (sold)
1969 Beetle (sold)


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