Re: CIS vs CIS-E (was: Idle Problems)

["Bradley Peet" <btpeet@effervescent.com>]

The Bentley manual for 75-84 R/J/S uses the term "CIS" to cover both the
older non-oxygen sensor version and the version with the ECU, oxygen sensor,
and frequency valve.  Both of these systems have a warm up/control pressure
regulator (that thing with two fuel lines that bolts to the front of the
block) that is the primary fuel mixture control mechanism.  (Note: the
frequency valve only fine tunes the mixture during warm running conditions
to reduce emissions.)

The Bentley for 85-93 Scirocco/Cabriolet uses the term "CIS-E " to refer to
the later version of CIS that has no warm-up regulator and no frequency
valve, but instead uses a coolant temp sensor, oxygen sensor, and (an
electronically controlled) differential pressure regulator to control
mixture.  This version is also called KE-Jetronic and is used on both 8V and
16V cars.

Chris is right on the knock sensor issue (CIS-E does NOT mean your car will
also have a knock sensor), but may be wrong in saying "if there is a
frequency valve on the fuel distributor than it is CIS-E".

Here's my summary of the three main the versions of CIS used on A1 cars:

FI System       CIS/E  ECU/Oxs  CPR   FV   DPR  KS
---------       -----  -------  ----  ---  ---  ---
L-Jetronic (?)  CIS    No       Yes   No   No   No
K-Jetronic      CIS    Yes      Yes   Yes  No   No
KE-Jetronic     CIS-E  Yes      No    No   Yes  16V only

CPR=Control Pressure (or "warm up") Regulator
FV=Frequency Valve
DPR=Differential Pressure Regulator
KS=Knock Sensor

I could be wrong on the FI system names, so please correct me if you've got
the Bosch FI service manuals handy.

On a side note, KE-Motronic (not used on A1 cars) is also a form of
CIS/CIS-E injection that is basically an upgraded version of knock sensing
ignition and KE-Jetronic merged into a single engine management system.
KE-Motronic looks similar to CIS-E injection and has TWO knock sensors on
the block.

Bradley
86 S16V 2.0l (KE-Motronic & TURBO install in progress)

>Date: Sun, 22 Aug 1999 04:49:46 -0400 (EDT)
>From: "Wm. Josiah Erikson" <josiah@bork.hampshire.edu>
>Subject: Re: Idle Problems
>
>Well then the Bosch service manual is wrong. CIS most certainly had
>frequency valves in many iterations. The difference in what you're talking
>about is the difference between various kinds of CIS. The system on the 8v
>Scirocco, for instance, is KE-Jetronic. It has an oxy sensor brain, a
>frequency valve, yadda yadda, but it is still referred to as CIS by all
>the Bentleys I've ever seen.
>
>On Sat, 21 Aug 1999, Chris DeLong wrote:
>>
>> OK, let's clarify here: CIS is the same injection system as on a '78
Rabbit.
>> CIS-E does not necessarily require a knock sensor. If there is a
frequency
>> valve on the fuel distributor than it is CIS-E. If there is an injection
>> brain then it is CIS-E, if there is an oxygen sensor it is CIS-E. All
this
>> str.aight from the Bentley FI Bosch service manual


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