FIAT 124 Spider
Engine Maintenance + Modification
76
10. The Major Tune Up
A major tune up is something you should have the knowledge and tools to do, or be
willing to learn. The procedures described in this section will have you completely “re-
set” your car, leaving you with a vehicle tuned to the factory specification and with all
new fluids. The idea is that you need your car to a neutral or baseline position before
trying to make any additional changes.
10.1 Preparation
Using the information you’ve already gathered (engine type, head type, etc.) you are
already on your way to establishing a baseline for your engine’s performance. It is
important to get a feel for how your existing setup operates before trying to change
anything. All of this work is easy and, armed with a shop manual for your model year;
you can do this in a couple of hours in your garage with minimal parts expense.
A suggestion before you begin: if you are new to working on cars or new to your FIAT
and note that the overall condition of your car is “worn” then consider the likelihood that
the replaceable parts under your hood are also worn. Be prepared to inspect and
purchase all of the ignition parts, hoses, shims, and belts. The expense will be minimal
and you’ll likely transform a “worn” car into one that performs just fine.
10.1.1 Ignition System
As necessary, you will need to install new plugs, wires, distributor cap, rotor, vacuum
advance capsule and hose, coil, pickup, points, and condensers, and set the timing, plug
and point gaps, and the dwell angle. Set the ignition timing to exactly what your car’s
instruction book calls for. If you have Marelli electronic ignition (1979-1985) check that
the vacuum advance is working properly. For each of these items follow the procedures
below.
Spark Plugs: If they look old, grimy, dirty, or anything but clean, replace them. You do
not need fancy spark plugs in your FIAT; your best bet is to use stock equivalent plugs
(some vendors actually sell the original equipment Marelli CW78LP, CW7LPR, and
CW67LPR and FIAT 1L4JR plugs). Spark plug gap for resistor plugs is 0.7 to 0.8mm.
Note: if the spark plugs have a greenish-white crystallization on them you likely have a
leaking head gasket that must be replaced before continuing.
Plug Wires: Brittle, hardened by heat, cheaply made, home-made, or unknown quality
wires should be replaced. As with the spark plugs you do not need an expensive set of
wires; the stock type works fine. When installing plugs coat the inside of the spark plug
boot with dielectric grease available from your auto parts store. If you like original parts
the Cavis ignition wires are available from some of the parts vendors.