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Need some help with a cis 8v

Subject: Need some help with a cis 8v
From: brianm at earendel.org (Brian McGarvey)
Date: Tue Apr 13 17:55:11 2004
In-reply-to: <200404132216.i3DMGSGA014722@hsb102.xlccorp.com>
References: <407AEE2B.7070701@techography.net><000d01c420d0$a7f82380$2eeb8545@main><200404122201.i3CM1kTb027964@hsb102.xlccorp.com><200404131827.i3DIR4Tn027508@hsb102.xlccorp.com><200404132216.i3DMGSGA014722@hsb102.xlccorp.com>

To all that have Probst's book
Look on Page 19. there is a picture. 
That shows the old setup CIS setup.

The Pressure regulator with push valve is the return path from the CIS 
distributor aka.. FUEL PRESSURE REGULATOR. The Control Pressure Regulator 
(CPR) is the thing mounted on the FRONT of the motor with an electrical 
connector and 2 fuel lines.


To those that Have the Compleat Idiot book (Green cover spiral bound 
version for the Rabbit) look on page 171 there is a picture that shows 
that it is basic spring valve just like almost every FPR in the auto 
world. Its just in the CIS distributor. 

Imagine this exploded view
oring - piston - spring - shim(s) - gasket - screw cap
and its set for 4.7 Bar.
This is what is hooked to the return line to the fuel tank.


 On Tue, 13 Apr 2004, David Utley wrote:

> Responses within...
> 
> Quoting Brian McGarvey <brianm@earendel.org>:
> 
> > 
> > David,
> > 
> > You need to look again at your own quote..
> > There is a FPR, CPR, (DPR on CIS-E), and an accumulator in the cars.
> > 
> 
> There is a Control Pressure Regulator, which is what I personally described, 
> but the FI book does not list, nor can I remember where there is regulator...  
> Where is this item, and what does it look like?

Pg. 19
its labeled in the picture.
it in the CONTINUOUS INJECTION -- Theory 
section 5.1.


> 
> > In the early CIS car the FPR is actually BUILT INTO the fuel distributor 
> > at the OUTPUT port of the fuel distributor. so it kind of goes like this
> > 
> > fuel tank (xfer pump some cars) fuel pump --> accumulator --> CIS 
> > dist(including CPR) --> Fuel Pressure Regulator --> fuel tank.
> > 
> 
> So, the fuel pressure regulator is on the return circuit?  If I understand 
> what you wrote above, then that is what I am reading...  It may be true, but 
> since I have gotten this wrong, I want to get it right...  LMK where I am 
> off...


In some early systems like carbs etc. used a dead headed system where the 
FPR regulated the pressure AFTER the FPR. In modern FI systems the system 
is called a closed loop system in that the fuel continously cycles thru 
the system. and the pressure between the Fuel pump and the FPR is 
regulated (kept) a particular pressure. within the response time of the 
Spring and Mass system in the FPR. 

Rising/falling rate etc FPRs are for a different discussion. 

> 
> > dont believe me belive your own quote...
> > 
> > Notice the BOSCH book lists it in just that order too...
> > 
> > 
> > In the later model cars the FPR is actually mounted on the outside of the 
> > CIS-E distributor.
> > 
> Here, what you are calling the FPR, is the differential pressure regulator, or 
> the control pressure regulator on the earlier cars...  Perhaps I am splitting 
> hairs here, but the terminology can be confusing on these FI systems...  
> Perhaps this is the source of Allyns' and my consternation?  
> 
> Cheers,
>   David
> 
> > On Tue, 13 Apr 2004, David Utley wrote:
> > 
> > > --Bosch Fuel Injection & Engine Management, By Charles Probst, SAE...
> > > 
> > > Continuous Injection-Theory, pg 11
> > > 
> > > "  In continuous systemes control of fuel pressure is extrememly important,
> > 
> > > even more so than in pusled systems.  As you'll see, fuel pressure opens
> > the 
> > > fuel injectors, and the control systems manipulate fuel pressure to alter
> > the 
> > > basic air-fuel mixture when  compensating for differeent operating 
> > > conditions.  It's vital that the fuel system not only supply adequate fuel
> > for 
> > > the amount of air the engine is using, but also that the fuel be under 
> > > pressure, maintained and controlled within a narrow range.
> > >   
> > > "  The fuel system includes the fuel tanks to store the fuel, the electric
> > 
> > > pump to pressurize the fuel, a
> > the fuel accumulator to damp pressure sugres in  the  system, 
> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > the filter, the fuel distributor to meter and distribute the fuel, 
> > 
> > > the pressure regulator to maintain primary system pressure,
> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> >  and the injectors 
> > > to atomize the fuel..."
> > > 
> > > Allyn, 
> > >   I quote this so that perhaps I can skip some of the dialogue back and
> > forth 
> > > and we both get to the meat of this topic...  What you are calling the fuel
> > 
> > > pressure regulator is in fact the accumulator.  It is right next to the
> > pump.  
> > > Its' job is to "damp fuel-pressure surges and to hold residual pressure in
> > the 
> > > system when the engine is shut off."  The "System-pressure regulator" is
> > the 
> > > item that hangs off the fuel distributor...  On the low-compression
> > engines, 
> > > it is bolted to the distributor (which is black in color) by means of a
> > clamp, 
> > > and it has a distinct fuel line to and from it, with a two-connection plug
> > 
> > > connected to it.  On the high-comp. engines, is is bolted directly to the
> > fuel 
> > > distributor (which in this case is machined aluminum), has no lines to it,
> > and 
> > > has IIRC a two-connection plug also...  Pg. 13, "The system-pressure
> > regulator 
> > > maintains system pressure (sometimes called preimary pressure) in the fuel
> > 
> > > system at the specified level."  It goes on to explain the two types, which
> > I 
> > > have already done...
> > > 
> > > Hopefully this clears up some of the confusion about these two items and
> > their 
> > > function...
> > > 
> > > Cheers, 
> > >   David
> > > Quoting Allyn <amalventano@sc.rr.com>:
> > > 
> > > > cis _does_ have a fpr, a 5 bar one, its mounted up front next to the fuel
> > 
> > > > distributor.
> > > > something has to regulate pressure at 75 psi, ya know...
> > > > Al
> > > > 
> > > > ----- Original Message ----- 
> > > > From: "David Utley" <mr.utility@highstream.net>
> > > > To: "Calimus" <calimus@techography.net>
> > > > Cc: "Allyn" <amalventano@sc.rr.com>; "Scirocco-l"
> > <scirocco-l@scirocco.org>
> > > > Sent: Monday, April 12, 2004 6:01 PM
> > > > Subject: Re: Need some help with a cis 8v
> > > > 
> > > > 
> > > > > Digifant would have a fuel rail, but CIS will not.  Also, not to split
> > 
> > > > > hairs
> > > > > here, but CIS does not have a FPR per-se, they do have an accumulator,
> > 
> > > > > that
> > > > > will not be your problem unless it is near completely clogged with
> > > > > something...  I think your trouble is either a grounding problem, or
> > the
> > > > > ECU...  I think it unlikely to be your fuel dist., unless one cylinder
> > is 
> > > > > not
> > > > > firing at all until, but that should be all the time, and not have 
> > > > > anything to
> > > > > do with the fuel dist....
> > > > >
> > > > > William, if you get that book I mentioned, you will figure it out, I 
> > > > > guarantee
> > > > > you...
> > > > >
> > > > > David Utley
> > > > >
> > > > > Quoting Calimus <calimus@techography.net>:
> > > > >
> > > > >> Hrm, I realized that I left something out.  The engine I'm refering
> > to
> > > > >> is/was a cis engine as well.  Basicly I transplanted the 8v from the
> > > > >> wifes old 89' cabby to the new 89' cabby.
> > > > >>
> > > > >> The fpr pretty much is my next stop.  If it still acts up then, only
> > > > >> things left I can think of are ecu, icm and the fuel pump.
> > > > >>
> > > > >> William
> > > > >>
> > > > >> Allyn wrote:
> > > > >>
> > > > >> > i would check the fuel pressure at the rail, or swap out the fpr.
> > it
> > > > >> > may not like the high volume from a cis pump (if you've still got
> > one
> > > > >> > in there).
> > > > >> > Al
> > > > >> >
> > > > >> > ----- Original Message ----- From: "Calimus"
> > <calimus@techography.net>
> > > > >> > To: "Scirocco-l" <scirocco-l@scirocco.org>
> > > > >> > Sent: Monday, April 12, 2004 3:29 PM
> > > > >> > Subject: Need some help with a cis 8v
> > > > >> >
> > > > >> >
> > > > >> >> Ok, basic description of the problem is that the engine appears to
> > > > >> >> have a miss at idle that stays noticable through the rpm range. 
> > Also
> > > > >> >> have to have the fuel mix very rich in order to keep it idling.
> > > > >> >> Engine also will not idle when first start, you must keep it
> > around
> > > > >> >> 2k rpm untill the engine warms up a bit.
> > > > >> >>
> > > > >> >> Now, here are the things I've checked or replaced.
> > > > >> >>
> > > > >> >> plugs (replaced)
> > > > >> >> plug wires (replaced)
> > > > >> >> dizzy cap and rotor (replaced)
> > > > >> >> injectors (replaced with used but from known running car)
> > > > >> >> Timing is dead on balls (cam/crank)
> > > > >> >> Compression check is good (160, 155, 162, 153)
> > > > >> >> Getting spark to all plugs
> > > > >> >>
> > > > >> >> I think that covers it.  This engine was recently swapped in,
> > using
> > > > >> >> the current fuel setup.  It ran fine in the car it came out of. 
> > The
> > > > >> >> previous engine had the warm up issue as well, but not this
> > missing
> > > > >> >> BS.  Any ideas are welcome.  I may have forgotten to list some of
> > the
> > > > >> >> things I did/checked but thats about the jist of it.  My current
> > > > >> >> thought is that it might be something with the fuel distributor but
> > I
> > > > >> >> thought I'd check with the list before I swap that out.  This is
> > on
> > > > >> >> my wifes 89' cabby BTW
> > > > >> >>
> > > > >> >> William S.
> > > > >> >>
> > > > >> >> -- 
> > > > >> >> 88' Scirocco 16v (Crabby 16v)
> > > > >> >> 89' Cabriolet 8v (Silver bunneh) 71' Karmann Ghia (air sucker)
> > > > >> >>
> > > > >> >> http://www.techography.com/scirocco (s.org forums)
> > > > >> >>
> > > > >> >>
> > > > >> >>
> > > > >> >> _______________________________________________
> > > > >> >> Scirocco-l mailing list
> > > > >> >> Scirocco-l@scirocco.org
> > > > >> >> http://neubayern.net/mailman/listinfo/scirocco-l
> > > > >> >
> > > > >> >
> > > > >> >
> > > > >> >
> > > > >> >
> > > > >>
> > > > >>
> > > > >> -- 
> > > > >> 88' Scirocco 16v (Crabby 16v)
> > > > >> 89' Cabriolet 8v (Silver bunneh)
> > > > >> 71' Karmann Ghia (air sucker)
> > > > >>
> > > > >> http://www.techography.com/scirocco (s.org forums)
> > > > >>
> > > > >>
> > > > >>
> > > > >> _______________________________________________
> > > > >> Scirocco-l mailing list
> > > > >> Scirocco-l@scirocco.org
> > > > >> http://neubayern.net/mailman/listinfo/scirocco-l
> > > > >>
> > > > >
> > > > >
> > > > >
> > > > > David Utley
> > > > > -----------
> > > > > Cable Volkswagen
> > > > > 405-470-3129
> > > > > 1-800-522-6793 
> > > > 
> > > > 
> > > 
> > > 
> > > 
> > > David Utley
> > > -----------
> > > Cable Volkswagen
> > > 405-470-3129
> > > 1-800-522-6793
> > > 
> > > _______________________________________________
> > > Scirocco-l mailing list
> > > Scirocco-l@scirocco.org
> > > http://neubayern.net/mailman/listinfo/scirocco-l
> > > 
> > 
> > -- 
> > -------------------------------------------------------------
> > Brian 
> > 88 16v $2004 GRM challenge car http://www.grmotorsports.com
> > 84 0v Next years car? mid engine... maybe we'll see
> > 82 0v Black 16v kit --parts
> > 82 2.0L Topless bunny -- Knock Ignition and bigger clutch. next.
> > 90 90q20v doing daily driver duty. 
> > 91 VFR750F everybody needs a 11-12 sec vehicle.
> > 
> > Contact method. Email me for AIM, ICQ, YahooIM, IRC, etc.
> > -------------------------------------------------------------
> > 
> > 
> 
> 
> 
> David Utley
> -----------
> Cable Volkswagen
> 405-470-3129
> 1-800-522-6793
> 

-- 
-------------------------------------------------------------
Brian 
88 16v $2004 GRM challenge car http://www.grmotorsports.com
84 0v Next years car? mid engine... maybe we'll see
82 0v Black 16v kit --parts
82 2.0L Topless bunny -- Knock Ignition and bigger clutch. next.
90 90q20v doing daily driver duty. 
91 VFR750F everybody needs a 11-12 sec vehicle.

Contact method. Email me for AIM, ICQ, YahooIM, IRC, etc.
-------------------------------------------------------------
Follow-Ups:
- Need some help with a cis 8v
  - From: mr.utility at highstream.net (David Utley)
References:
- Need some help with a cis 8v
  - From: calimus at techography.net (Calimus)
- Need some help with a cis 8v
  - From: amalventano at sc.rr.com (Allyn)
- Need some help with a cis 8v
  - From: mr.utility at highstream.net (David Utley)
- Need some help with a cis 8v
  - From: mr.utility at highstream.net (David Utley)
- Need some help with a cis 8v
  - From: mr.utility at highstream.net (David Utley)
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