[alfa] RE: Fuel quality switch settings - Bosch Motronic ECU

["John Fielding" <johnf@xxxxxxxxxxxxxxx>]

In the Bosch Motronic Service manual for the Alfetta (same system used on European
Spiders, the N.A. vehicles may be different!) the FQS settings are as follows:

position 1 (stock)    Fuel adj 0%        Ign adj  degrees
position 2                 +2 to 4%            0
position 3                  +4 to 7%            0
position 4                  -2 to 4%             0
position 5                  0                         -2 to 4deg
position 6                   +2 to 4%            -2 to 4deg
position 7                   +4 to 7%             -2 to 4deg
position 8                    -2 to 4%             -2 to 4deg

So you can see that you cannot get any additional igntion advance to improve the
performance, only ignition retard.  The purpose of the switch is as its name suggests,
to overcome problems of detonation due to poor fuel quality.

Remember the FQS must only be moved with the ignition switched off.  If you change the
setting with the engine running the switch will be ignored and the settings read by the
processor at switch-on are used.

I hope this helps.

John
Durban
South Africa
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