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[WERNER_HAUSSMANN at HP-Loveland-om2.om.hp.com]

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Hi James

The L-Jetronic uses an air meter with a flap.  Yes it is restrictive. My 
original plan was to get this system going.  Put in the fuel delivery 
system, get the injector(s) working and just prove the feasabilty.  Then I 
was going to move up to the fancy $1800 Electromotive TEC II system.  It 
uses a Mass Air Flow meter.

Anyway the L-jetronic seems to work well enough to satisfy me, but I am 
still itching to add a turbo, and for that I want to control the ignition 
and will probably need the Electomotive system.

A later Bosch system called the LH-Jetronic was digital and used a MAF 
meter.  This was used in the '80s on Volvo up to '88. The L series Bosch 
systems are very nice because they are so easy to adapt.  They only use the 
ingnition coil signal.  No fancy crank sensors are needed.

Anyway the problem for hot rodders are that these systems were used mainly 
in relatively small engines except for Jaguar, BMW and the like.  And for 
the price of those in a junk yard, you might as well use Electromotive 
systems.

The L-Jetronics uses only the air meter signal (air temperature and Air 
flow, together they give air volume), the water temperature and the 
ignition (rpm and crank position) to calculate Fuel.  Trottle position is 
not used except to enrich at 2/3 trottle and to cut out the fuel above 1500 
rpm when at closed trottle. This is actually very accurate and very simple.

The air meter gives out a voltage that changes logorithmically with the air 
flow. It also has a thermistor for air temperature. 

To use the L-Jetronic system You will have to find a car with about the 
same size engine as the one you want to adapt.  This is most likely to be 
your biggest obstacle.  Of course you could run two systems, one on each 
side of a V8.  How big an engine are you using anyway?

My suggestion is that you should try to get something working, and then 
keep working to make it better. You can always try to get started with the 
Holley trottle body.  Used ones are often for sale by someone who has 
upgraded.  This way you will get the basics in place like the fuel 
delivery, the high pressure pump, etc.

For more information get the Probst book on Bosch systems.

Good Luck
Werner