See Figures 1, 2, 3 and 4
The Thick Film Integrated (TFI) ignition system was incorporated on 1.6L engines, in late 1982. In 1983, two versions of the Thick Film Ignition system were used. The original version from 1982, also known as TFI-I, was carried over for 1.6L Non-EFI and 1.9L Non-EFI engines; another version, known as TFI-IV, was used on all engines equipped with Electronic Fuel Injection (EFI). Engines equipped with TFI-IV use redesigned spark plugs which have an extended reach 14mm tapered seat, a multi-point rotor and a universal distributor, which eliminates the conventional centrifugal and vacuum advance mechanisms, used on the earlier Dura Spark II Ignition System.
The distributor used on 1.6L Non-EFI and 1.9L Non-EFI engines is a carry-over design distributor with top weight centrifugal advance mechanism and concentric coil stator assembly. The distributor used on 1.6L EFI engine is a universal distributor design which has a tang-driven die cast base. This distributor incorporates an integrally mounted TFI-IV module, a vane switch stator assembly which replaces the current coil stator. The distributor also contains a provision for fix octane adjustment. The overall design of this distributor eliminates the conventional centrifugal and vacuum advance mechanisms.
The basic operation of the distributor (with concentric coil stator assembly) is the same as the Dura Spark II ignition system. The rotating armature induces a signal in the stator assembly, causing the ignition module to turn the ignition coil current ON and OFF .
During model years 1986-90, operation of the universal distributor assembly used on the 1.9L EFI engine is accomplished through a Hall effect vane switch assembly, which causes the ignition coil to be switched OFF and ON by the Electronic Engine Control-IV (EEC-IV) computer and TFI-IV module. The vane switch is an encapsulated package consisting of a Hall sensor on one side and a permanent magnet on the other side. The distributor contains a provision to change the basic distributor calibration with the use of a replaceable octane rod, from the standard of 0° to either 3° or 6° retard rods. No other calibration changes are possible. The TFI-IV system featured a "push start" mode which allows manual transaxle vehicles to be push started. Automatic transaxle vehicles cannot be push started.
A rotary armature, made of ferrous metal, is used to trigger the Hall effect switch. When the window of the armature is between the magnet and the Hall effect device, a magnetic flux field is completed from the magnet through the Hall effect device, and back to the magnet. As the vane passes through the opening, the flux lines are shunted through the vane and back to the magnet. A voltage is produced while the vane passes through the opening. When the vane clears the opening, the window causes the signal to go to 0 volts. The signal is then used by the EEC-IV system for crankshaft position sensing and the computation of the desired spark advance based on the engine demand and calibration. The voltage distribution is accomplished through a conventional rotor, cap and ignition wires.