Re: Motronic or KE-Jet?

[ti@amb.org (Ti Kan)]

JShadzi@aol.com writes:
> 	Motronic is EFI, so look for electronic fuel injectors with a fuel 
> rail above them.  If you have the metal braided fuel lines, it is still KE 
> (CIS-E), or could be CIS-III, but Im not familiar with the distiction between 
> the two on the 4 cylinder because I believe even the normal KE had a knock 
> sensor.  On the I5, there is a knock sensor on the CIS-III, where there was 
> not on the KE.  I have a book on this, I will check it out and try to get 
> back...

Sorry for a long winded reply below, but I believe there is confusion of
terminologies here...  You are confusing L-Jetronic with Motronic.

The K and KE-Jetronic family of injection systems use a fuel distributor
with an air flow sensor plate and the injectors spray "K"ontinuously
while the engine runs.  The L-Jetronic on the other hand uses
eletronically-controlled injectors mounted on fuel rails that spray
in pulses.

Early K systems are completely mechanical with no electronics
other than the electrical fuel pump and the heating elements in various
regulators.  Early-80s K systems got an analog ECU and frequency-valve
controlled OXS system.  The KE systems changed to using a differential
pressure regulator that is controlled by the ECU.  The L systems always
had an ECU, the LH systems uses a hot wire air mass sensor instead of the
earlier air flow flap.

All early versions of K and L based systems, if it has an ECU at all,
generally manage only the fuel system and not the ignition.  The ignition,
if electronic, usually had a separate control unit.

Bosch calls a system "Motronic" when the fuel and ignition systems are
integrated into one digital ECU.

BMW and Porsche began using L-Motronic since around 83-84 or so, and Audi's
first use of K-Motronic in a U.S. model (in a non-turbo application) is
the 1988-89 Audi 80 4-cylinder.

Curiously, the system used in the Audi 5000 turbos and UrQ is
"K-Jetronic" even though it had all the characterics of a "Motronic"
system (fuel, spark and boost all managed by one digital ECU).  This
is probably because these Audi systems used Hitachi ECUs instead of Bosch.

To make this all even more confusing, VW and Audi chose to call the K
systems CIS, CIS-E and CIS-III, corresponding to K-Jetronic, KE-Jetronic,
and KE-Motronic.

-Ti
96 A4 2.8 quattro
84 5000S 2.1 turbo
80 4000 2.0
-- 
    ///  Ti Kan                Vorsprung durch Technik
   ///   AMB Research Laboratories, Sunnyvale, CA. USA
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