According to 'Bosch Fuel Injection & engine Management", by Charles
     Probst:

     The first continuous injection system (CIS) (1977) was K-Jetronic.
     Air flow
     is measured by a circular plate in the air-flow sensor, which is
     mechanically linked to the fuel distributor.  Until 1980, fuel
     delivery is
     strictly under mechanical control in direct relation to air flow;     there are     no electronics.  VW, Audi, and Mercedes call it CIS.

     K-Jetronic with Lambda Control is an adaptation of K-Jetronic

mechanical

     control.  The mixture is modulated with a limited electronic control
     in a
     feedback system to maintain a precise air-fuel ratio.

     KE-Jetronic combines K-Jetronic mechanical control with total
     electronic
     modulation of the mixture.  It uses many of the same sensors used in     L-Jetronic (a pulsed fuel injection system).  It's capable of full     mechanical fail-safe if the electronics fail.  VW, Audi, and     Mercedes call     is CIS-E.

     Andy Hecker
     CIS in a '77 Rabbit (RIP)
     Digifant II in an '88 Jetta

     -------
     Paul,

        First - I'm sorry for the typos, and 'editing' compliments of MS word     'autocorrect'.  It didn't like 'Jetronic' apparently.  The systems     described     above are all 'Jetronic', not 'electronic(s)'.

        Second - the author of the 'Bosch..." book said his production year     references (like the 'first seen in 1977' comment above were for the US     market only.

        The chart lists injection in VWs from the Type 3s...

        On the history front - also from the Bosch book:

       "Bosch passenger-car fuel injection first appeared in 1927 as a diesel     design using engine-driven pumps developing high pressure to deliver     diesel     fuel into the cylinders - direct injection.  In 1937, these pumps were     adapted to aircraft engines, with both diesel and gasoline fuel     applications.  In 19565, similar engine-driven gasoline injection     pumps were     developed for the Mercedes-Benz race cars and the 300SL production car,     again injecting fuel at high pressure directly into the cylinders.

       "The fuel-injection systems described in this book first appeared
     about
     1967.  They are completely different from engine-driven systems,
     delivering
     fuel at much lower pressures at the intake ports, and are generally
     electronically controlled.  The early Bosch literature describes these     systems as "non-driven".  Bosch coined the term "Jetronic" to     establish a     common identity for their new designs in most of the 135 countries     in which     they operate.

     Andy
     -7 from the Russian judge for (lack of) editing...

More "me too"..  My '74 Volvo (wagon) had K-Jetronic.  '71's had dual SU side drafts (our first Volvo) - lame.  '72's had electronic FI (I think one year only - maybe the P1800's had more years).  And I think '73 through about '78 had K-Jetronic.  By '82 (our newest Volvo) they had Lambda (O2 sensor).

The K-Jetronic ran fine, but had kind of weak throttle response.  As far as throttle response, the sportiest Volvo I've driven is our '67 122S with dual SU HS6's.  Kind of surprising since they don't have an accelerator pump..

Matt-

Matt,

The SU uses oil damping of the air piston to slow down the opening of the

throat. This increases venturi velocity and vacuum and thus fuel flow when
throttle is opened, without to much extra air. Thick oil gives a rich mixture
for acceleration. Very thin or no oil generally leads to a stumble on quick
throttle opening. Underbonnet temperature changes the viscosity and the
effect of the damping and ruins all the careful tuning.

Colin Smith


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