AFM calibration?

[Walter Petermann]

If you have some time to experiment, you might try adapting
a hot-wire air flow sensor. That I know of you would have
to make the following modifications:

i)   amplify the output
ii)  replace the original air temp sensor with a fixed
     resistor.
iii) the L-jet flow meter has built in contacts to turn on
     the fuel pump relay so you'd have to take care of this
     some other way.
iv)  Hot wire flow meters have a circuit to REALLY heat up 
     the wire and burn off dirt and deposits. If I remember 
     right this happens when you shut the engine off. You'd
     have to get some info on that.

I was trying to find a schematic of a hot wire flow sensor
that I took to pieces once. No luck! If I do find it I'll
email it to you.

regards,
 Walt

 

Francois Dion wrote:
> 
> I know nobody would want to use an airflow meter
> as used in an L-jet setup nowadays, however I have
> an older car that has that restrictive setup and I'd like
> to adjust it for better flow. How can I know what is a good
> tension on the spring?  I know the looser, the better
> airflow, however I think this can bring me a few
> problems if it's too loose. I know this affect the
> fuel economy as the hp goes up (in combo with
> a free flowing air filter of course) but what other
> side effects are there?
> 
> Should I instead forget the AFM and try to find
> another sensor that could be used instead? The
> setup is Bosch L-jetronic in a Lancia Zagato. I do
> believe it's the exact same setup as in a Fiat 2000
> spider. All components are 81 except the AFM
> which is a 79 and is the all aluminium type (except
> for the cover over the spring).
> 
> Ciao,
> Francois Dion (francois at hyperreal.org)
> --
> Member: FLU #1722, PCNA
> http://www.fortunecity.com/silverstone/zagato/101/launch.html
> Alfa Romeo, Fiat, Lancia, Peugeot, Volvo, Solex