Ignition System - Mitsubishi Electronic Mazda 626 GC

DESCRIPTION

Mazda B2000 Pickups models with Calif. and High Alt. emissions, use a vacuum delay valve during acceleration. Calif. B2000 Pickups also use a water thermo valve to cut advance during cold operation.

OPERATION

Whenever the ignition switch is in the "ON" position, the primary circuit of the ignition coil is energized. As the distributor shaft rotates, the armature (reluctor) rotates inside the magnetic pick-up coil (stator) assembly.

As the teeth of the armature pass the pegs of the pick-up coil, a signal is sent to the control module (ignitor). The module then breaks the primary circuit in the coil. This causes a high voltage surge in the coil secondary circuit. This high voltage is required to fire the spark plugs.

Wiring Schematic of Electronic Ignition System W/Internal Control Module. Scheme 1

ADJUSTMENTS

Note. Air gap is not adjustable if model is not listed in table.

RELUCTOR-TO-PICK-UP COIL AIR GAP

Align teeth of reluctor with pegs of pick-up coil and breaker plate assembly. Using a feeler gauge, check for correct air gap. To adjust, loosen set screws, and move pick-up coil.

Note. No adjustments should be attempted on the ignition system except pick-up coil air gap, spark plug gap, and initial ignition timing.

TESTING

Note. Be sure battery is at full charge and in good condition before making any tests. Check all wiring harnesses, ignition switch, coil and spark plug cables and connectors.

HIGH VOLTAGE TEST

Connect a remote starter switch in the starting circuit. Remove coil wire from distributor cap. Turn ignition switch to the ON" position and hold coil wire 1/4" from cylinder block. Crank engine. If no spark or only a weak spark results, perform the following tests.

SECONDARY WIRE RESISTANCE TEST

1. Test coil and spark plug cables with an ohmmeter. Do not puncture secondary wires when making the resistance check. Connect leads to each end of the cable.
2. Resistance for Mazda and Mitsubishi vehicles should not exceed 16,000 ohms for each 39" (1 m). For Chrysler Corp. vehicles, resistance should not exceed 22,000 ohms per cable.

IGNITION COIL RESISTANCE TEST

1. Turn ignition switch to the "OFF" position. Remove wires from coil primary terminals to isolate it from the rest of the system. Set an ohmmeter in the low scale, and attach the leads to the coil positive and negative terminals. Check primary resistance reading.
2. Set ohmmeter in x1000 scale, and attach leads to the coil positive terminal and secondary tower. Check secondary resistance reading.

DISASSEMBLY

1. Remove distributor cap and rotor. Remove governor assembly. Note location of 2 different governor springs, for reassembly in original location. Remove attaching screws. Remove pick-up coil and IC ignitor assembly. NOTE: Governor assembly locking bolt is very tight. Use either a box wrench or socket wrench.
2. Pull out the ignitor carefully from pick-up coil (if applicable). Remove the vacuum control unit. Remove the breaker assembly. Mark gear and shaft for reassembly reference. Remove pin holding gear to shaft and remove gear. (Scheme 2)

Note. DO NOT clean grease off back of IC ignitor. It is necessary for heat transfer.

Installing Driven Gear on Distributor Shaft. Align match marks and install pin. Scheme 2

Exploded View of Mazda GLC Distributor. Note location of governor springs for reassembly. Scheme 3

REASSEMBLY

Reverse removal procedure. Inspect cap and rotor for cracks and deposits on inside surfaces. Be sure no metallic dust or filings adhere to breaker assembly, and is clean prior to reassembly.

Exploded View of Mitsubishi Distributor with ECI. Note location of governor springs for reassembly. Scheme 4

COIL RESISTANCE SPECIFICATIONS

IGNITION COIL RESISTANCE SPECIFICATIONS (OHMS)

Scheme 5

1. Turn ignition switch to the "OFF" position. Set an ohmmeter in the x100 scale. Attach leads to pick-up coil's distributor connector terminals. (Scheme 5) (Scheme 5): Checking Pick-Up Coil Resistance. Attach ohmmeter leads to points shown.
2. Compare resistance readings obtained with table. See PICK-UP COIL RESISTANCE table.

PICK-UP COIL RESISTANCE

IGNITION MODULE TEST

Note. This test can only determine when ignitor is bad. Even if ignitor tests out as good, it could still be defective.

Checking Ignitor With Battery and Test Lamp. Use low-voltage dry cell battery or ohmmeter. Scheme 6