Fiat 124 Spider - Ignition Advance

FIAT 124 Spider
Engine Maintenance + Modification
68
barrel type mounted to the inside of the driver’s side fender on the early models and the
passenger side on the late models.
The electronic ignition system of the 1979-1985 Spiders can be identified by the large
coil pack mounted on the passenger side fender wall. If stock it will have an enclosure
of aluminum fins to each side and a control module on the bottom back. Most electronic
distributors will be stock, with a vacuum canister mounted on the side. Two wires
wrapped in a small diameter tube run from the distributor pickup to the coil pack. The
now rare FIAT replacement part known as the Marelliplex system looks identical except
that it has no vacuum canister on the side of the distributor (and no way to install one; a
sure way to identify a fake Marelliplex is to see if the base has the opening and fitting for
the vacuum dashpot).
Table 9: Ignition System Components
Series Seal Cap Rotor Condenser
Breaker
Points or
Pickup Unit Coil Unit
AS 9915908 9925467 9924654 9913848 9913862
BS1 9921512 9925467 9924394 9922454 7111161
CS1 9921512 9925467 9924394 9926424
(74-77)
9929180 (73)
7111161
CS2 9921512 46340 56290 859818 9937730 4386220
CS0 9921512 46340 56290 859818 9937730 4386220
DS0 9921512 46340 56290 859818 9937730 4386220
9.3 Ignition Advance
In your Spider the basic ignition timing is set to either 5 degrees (1438cc), 0 degrees
(1592cc, 1608cc 1756cc) or 10 degrees (1978 1756cc and all 2000cc) behind top dead
center (BTDC). This means that the spark plugs “fire” when the crankshaft angle is
almost at the absolute top of travel. This is called ignition advance. Advance is a term
applied to timing an engine in such a way that the spark is delivered just before the
piston reaches top dead center. This is necessary because there is a time lag between