I will take up for CIS and CIS-E here.  Owned and worked on several
A1 chassis VWs and autocrossed them as well.  I remember one had
issues with the auxiliary air regulator.  The thing that adjusts the
idle speed as the engine warms up.  I took the thing apart and fixed
it.  I think I had one failed fuel pump also.  What really sold me
was the 85 GTi I owned from about 90k to 215k miles.  That was CIS-E,
which was the purely mechanical system with electronic influences for
more subtle control.  Never a lick of trouble out of that fuel system
in the time I owned it.  Just change the filters regularly I
guess.  Back then, the racers hated "digifart" and reported that the
stock CIS system was good for engines modified up to about
250HP.  The stock engines were in the 75-100HP range back then.  I
remember once in my stock 79 Scirocco wanting to hold 2nd gear a
little longer before a turn.  When I finally turned in and looked at
the tach, the needle was off the scale and down into the fuel
gauge.  Durable little engine...
Edward

At 08:57 PM 11/16/2009, pdooley wrote:
>CIS is pretty robust.  Works great up until you get junk past the filter and
>into the system.
>The control pressure regulator clogs, injectors start spraying weird
>patterns, and God help you if the fuel distributor fouls.
>Then you have things like the accumulator that leak fuel underneath the
>vehicle and those #@$%& copper crush washers everywhere, pretty much
>one-time use only.
>However the CIS fuel pumps hold up well; I had a 22 yr old Scirocco with the
>original.
>
>If you ever look closely at a CIS system you can really appreciate the
>precision machine work and quality of materials.  The airflow housing is a
>beautiful thing with glassy smooth pivot bearings, machined aluminum funnel
>and anodized counter weight.  The fuel distributor flow orifices are laser
>cut and the plunger is such a precise fit that pressurized fuel doesn't leak
>out even with no rubber seals or o-rings.
>
>CIS is kinda like the last steam powered locomotives- brilliant masterpieces
>of mechanical ingenuity, though hopelessly complex and cumbersome.
>
>Some would argue modern EFI is hopelessly complex, but not from a mechanical
>point of view.  And with OBD, a simple scan will find most problems and let
>you know about it in plain English.
>Diagnosing CIS problems OTOH takes a little skill.
>
>
>-----Original Message-----
>From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
>neil n
>Sent: Monday, November 16, 2009 4:40 PM
>To: vanagon@GERRY.VANAGON.COM
>I can't help but wonder if CIS hasn't gotten a poorly deserved bad rap
>over the years. To me it seems like a simple system (CIS, not CIS-E)
>that would be quite reliable. Mind you, a rebuilt fuel distributor
>looks pricey, (are they even available new?) but I bet it takes quite
>a few miles before that part fails. And if one keeps an eye on those
>high pressure fuel lines, why not keep it?
>
>Neil.
>
>
>--
>Neil Nicholson '81 VanaJetta 2.0 "Jaco"
>
>http://tubaneil.googlepages.com/
>
>http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engine
>s