FIAT 124 Spider
Engine Maintenance + Modification
85
there with the electronic system. The trade-off is the older types require more
maintenance. If you want to eliminate this maintenance at the sacrifice of originality, you
have options.
The 1979-1985 electronic ignition system is a popular and easy upgrade from all previous
types (dual and single points). Installation of the late model system is straightforward,
you’ll need the distributor body (preferably rebuilt fully) in proper operating condition, and
the coil pack. The system directly replaces the old components and is tuned in the same
manner. There is an economic downside to the electronic ignition system conversion; to
make it work properly you must have a carburetor ported above the throttle plates. The
stock carburetors with this option are the 32 ADFA and the 28/32 ADHA; the aftermarket
carburetors are the 34 ADF, 36 ADL, 38 ADL, and 32/36 DFEV.
Figure 47: Location of port for vacuum advance
The figure of the ADFA carburetor above shows the location of the vacuum port, on the
main carburetor body above the throttle mechanisms. Unlike earlier models these
carburetors have a two piece construction and this port is tapped into the base of the
upper portion, just above the mixture screw. Without this connection the vehicle ignition
will not work properly and performance will degrade below that of the mechanical
system you’ve replaced.
The Marelliplex electronic ignition system is an option for those of us who do not want
to find ported vacuum. Marelliplex units are available as block-mounted (for 1438cc
motors) and cam-box mounted (for all other motors). Unfortunately, the cam-box mount
type is nearly impossible to find and will typically cost more than a new carburetor. The
block-mount is more common and shared with the Lancia beta, but will only fit well on
the 1438cc and 1608cc motors. There are manifolds for the 1756cc with a slight
indentation that will allow the distributor to fit the other motors, but the difficulty of
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