Date: Mon, 16 Nov 2009 22:05:11 -0500
Reply-To: Edward <emaglott@BUNCOMBE.MAIN.NC.US>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Edward <emaglott@BUNCOMBE.MAIN.NC.US>
Subject: Re: Why not CIS? RE: Images of South African van on website
In-Reply-To: <0KT800EW4DFGS5YK@vms173015.mailsrvcs.net>
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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
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