Ignition System - Hall Effect Chrysler LeBaron II

DESCRIPTION

The Electronic Spark Control system features a Hall Effect distributor, as many as 5 engine sensors, and a Spark Control Computer (SSC).

Wiring Diagram for Hall Effect Electr Spark Control System on 2.2L EFI Enginesonic. Scheme 175

Note. The same distributor is used on 2.2L EFI engine and 1.6L and 2.2L engines. The 2.2L EFI engine also uses a logic computer to advance timing.

Wiring Diagram for Hall Effect Electr Spark Control System on 1.6 & 2.2L Non-EFI Enginesonic. Scheme 176

SPARK CONTROL COMPUTER

The computer ignites lean air/fuel mixtures according to different engine conditions. It provides an infinite number of variable advance curves.The computer receives signals from engine sensors. It analyzes the signals to determine engine operating condition and then adjusts ignition timing.

The computer determines when ignition is required, and signals the ignition coil to produce an electrical impulse to fire the spark plugs. The computer is part of the engines air intake duct, located on the fenderwell. Engine sensors include a vacuum transducer (mounted on the computer housing), Hall Effect pick-up assembly, engine coolant temperature sensor, carburetor switch (if equipped), and an oxygen sensor.

Hall Effect Pick-Up Assembly

Located in the distributor, it sends alternating current signals to the computer as rotor shutter blades enter and leave the gap in the Hall Effect switching unit pick-up assembly. The pick-up supplies basic timing and engine RPM signals to the computer. The computer uses pick-up signals and other sensor input to provide maximum amount of advance for engine operating conditions.

Components of Hall Effect Distributor Electronic Spark Control System for. Scheme 177

Carburetor Switch

Some models may be equipped with carburetor switch which reports when the engine is at idle. It is located on the end of the throttle stop.

Coolant Temperature Sensor

Located on the thermostat housing, the coolant temperature sensor keeps the computer informed on engine operating temperatures.

Vacuum Transducer

The vacuum transducer informs the computer of engine manifold vacuum. Engine vacuum signal helps govern spark advance and, with feedback carburetor vehicles, alter the air/fuel ratios.

SYSTEM OPERATION

The computer has 2 functional modes: "Start" and "Run". "Start" mode functions only during engine cranking and starting. A fixed amount of spark advance is provided, based on distributor position. "Run" mode functions only when engine is running.

The amount of spark advance is determined by 3 factors: coolant temperature, engine speed, and manifold vacuum. The computer has a different advance schedule for a hot and a cold engine.

Timing advance is programmed into the computer. In a cold engine, advance depends only on amount of manifold vacuum. In a hot engine, advance depends on both manifold vacuum and engine speed. The advance curve is further modified by the carburetor switch. For maximum advance, carburetor switch must remain open.

If "Run" mode fails, system will go into "Limp-In" mode. This enables vehicle to be driven in for repair. Performance and fuel economy will be poor. If Hall Effect pick-up or "Start" mode of computer fails, engine will not start or run.

ADJUSTMENTS

No adjustments can be made to Hall Effect pick-up unit. Dwell and spark timing cannot be adjusted in the "Run" mode. Fixed timing ("Start" mode) can be adjusted by changing distributor position.

TESTING

Note. Testing procedures for the Electronic Spark Control System are covered in the appropriate article in the COMPUTERIZED ENGINE CONTROLS section of ENGINE PERFORMANCE.

Scheme 178

1. Remove distributor with ignition wires from vehicle. Clamp distributor in soft-jawed vise. Remove 2 screws holding splash shield to distributor housing. Remove distributor cap and rotor from shaft. NOTE: When removing spark plug wires from distributor cap, do not pull on wires. Positive-locking wires must be released from inside cap. (Scheme 178) (Scheme 178): Releasing Positive-Locking Spark Plug Wires
2. Remove Hall Effect pick-up assembly lock springs (or clips) and lift pick-up assembly out. Mark drive gear (or distributor drive) position on distributor shaft. Using a pin punch, drive roll pin from shaft.
3. Remove drive gear (or distributor drive) and remove shaft from housing. If equipped, remove thrust washers, nylon spacers and block seals.

REASSEMBLY

To reassemble, reverse disassembly procedure. Correct rotor has "E.S.A." stamped in its top. Check rotor for proper grounding of shutterblades.