Engine Maintenance and Modification Bradley Artigue
FIAT 124 Spider Engine Maintenance + Modification - Artigue.com
FIAT 124 Spider Engine Maintenance + Modification - Artigue.com
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FIAT 124 Spider<br />
<strong>Engine</strong> <strong>Maintenance</strong> + <strong>Modification</strong><br />
Spark Plugs have electrodes suspended in the combustion chamber <strong>and</strong> are connected<br />
to a cap on top of the distributor by wires. When the distributor releases the coil’s<br />
energy it travels through the cap, into plug wires, <strong>and</strong> into the spark plugs. The resulting<br />
spark ignites the fuel/air mixture in the combustion chamber.<br />
Plug Wires are designed to contain the high energy of the coil <strong>and</strong> deliver it to the spark<br />
plugs. They are the largest wires in the engine compartment <strong>and</strong> are quite obvious as<br />
they run the top of the cylinder head.<br />
Points are small electrical switches that open <strong>and</strong> close as the distributor rotates. When<br />
the points are closed an electrical field builds up in the ignition coil. When they open the<br />
field collapses, releasing energy into the spark plug.<br />
A Condenser is a small (typically silver) barrel on the body of the distributor. It absorbs<br />
misdirected (for lack of a better term) energy that runs from the coil back to the points<br />
instead of to the spark plugs. Without a condenser the points will deteriorate quickly or<br />
weld themselves together.<br />
The Magnetic Pickup is the equivalent of points on the electronic ignitions installed in<br />
the 1979-1985 Spider. Instead of the striking motion <strong>and</strong> inevitable wear associated with<br />
points, a magnetic pickup literally “picks up” the increasing <strong>and</strong> decreasing magnetic<br />
wave created by lobes in the distributor shaft. The energy from the coil is released by a<br />
control module located on the coil itself.<br />
The Control Module is located on the coil pack of the 1979-1985 Spider. It<br />
electronically collapses the coil’s electrical field.<br />
The Vacuum Module is a dashpot located on the side of the 1979-1985 Spider<br />
distributor. A diaphragm inside the dashpot is connected to a shaft that pulls or pushes<br />
the advance plate. The diaphragm is moved via vacuum pulse from the throttle body.<br />
On fuel injected cars it is connected to a port located near the throttle on the air flow<br />
meter side of the throttle plate. On carbureted Spiders the port is located just above the<br />
throttle plates. In both cases when the throttle opens a drop in air pressure pulls on the<br />
diaphragm which in turn moves the advance mechanism.<br />
9.2 Ignition System Identification<br />
All Spiders made prior to 1979 had breaker points. A single-point distributor will have a<br />
coil mounted to one of the inner fenders <strong>and</strong> a single condenser on the distributor body.<br />
It is the least complex of the Spider ignition systems. A dual-points distributor is similar<br />
to the single-point but has two condensers on the body <strong>and</strong> two sets of points on the<br />
interior. Some 1973-1978 Spiders have had the dual-points removed (replaced with a<br />
single point internally) or the entire distributor replaced with the single-point model. The<br />
single <strong>and</strong> dual point distributors can be identified externally; single-point distributors<br />
have a single condenser <strong>and</strong> wire (blue/black) running off of the distributor. Dual-point<br />
distributors have two wires (green <strong>and</strong> green/black). The coil for both units is a common<br />
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