KISS System

[Sandy]

My 323i has the Bosch K-Jet and it works OK, not when its cold or hot. It
is a pretty scary system, and although it looks simpler then the electronic
types, it is far from simple. Lots of mechanical things that can fail that
will hose the system, cold start valves, air valves, the rubber intake
belows, etc. It has/had an O2 sensor connected to an aftermarket module
that operated an bypass (looks like an injector) to adjust the fuel mixture
by adjusting the pulse width of the bypass. If you are really looking for a
KISS injection, get a Hilborn, it has a pump, a barrel valve, a bypass, and
that's all. They dont work that great unless expertly, and constantly tuned
however. 

Sandy

At 09:57 AM 2/23/98 -0500, you wrote:
>>>     I may be stupid about electronics, but it seems to me that most of
>>> the EFI systems out there are way too complex.  Anybody out there
>>> building a KISS EFI system that doesn't require operator intervention?
>>
>>Yep,  been twiddling with an idea for the Bosch K-jetronic system, which
>>is what you were describing.  All my system adds is an O2 sensor and a
>>stepper motor that will manually controll the control pressure regulator,
>>the system will run closed loop, as soon as  a temp sensor trips.  So the
>>system will run normally at startup (rich), and when the enging gets up to
>>temp, the O2 sensor will begin to feed signals to a box that just
>>increments the stepper motor in the proper direction, affecting control
>>pressure up, or down, as needed.  The main disadvantage is the system is
>>constantly trying to seek out the best mix, and tends to overshoot it,
>>though that is a minor control system problem.  If an O2 sensor from those
>>new Toyotas was available then a perfect mix could be obtained and
>>controlled within a tight ratio.
>>
>>Dave
>
>
>Dave (and whoever else is interested),
>
>Later Bosch CIS systems had an O2 sensor in the loop, so you might not have
>to re-invent it.  My 1980 Porsche 924 turbo has an O2 sensor that controls
>the fuel distributor.  I believe later rabbits and others with CIS-E
>systems used similar, and are available for next to nothing at auto
>dismantlers all over.
>
>
>
>Best Regards,
>
>Darryl Snover
>Senior Programmer
>Technologies Plus, Inc.
>
>
>
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