Preliminary Checkout, Equipment and Notes
13-78Ignition Systems, Timing Procedures and Diagnostics
Preliminary Checkout, Equipment and Notes
CHECKOUT
^ Visually inspect the engine compartment to ensure all vacuum hoses and spark plug wires are properly and securely connected.
^ Examine all wiring harnesses and connectors for insulation damage, and burned, overheated, damaged pins, loose or broken conditions. Check sensor shield connector. Make sure DIS Module mounting screws are tight.
^ Be certain the battery is fully charged.
^ All accessories should be off during diagnosis.
Figure 1 - 2.3L EFI Truck (Dual Plug) DIS Hook-Up:
EQUIPMENT (Required)
Obtain the following test equipment or an equivalent:
^ DIS Diagnostic Cable (Rotunda 007-00044 or equivalent) (refer to Figure 1).
^ Spark Tester, Neon bulb type (Champion CT-436 or equivalent).
^ Volt/Ohm Meter (Rotunda 014-00407 or equivalent).
^ Remote starter switch.
^ EEC-IV breakout box (Rotunda T83L-50-EEC-IV or equivalent).
^ Spark Tester, Gap type (Special Service Tool D81P-6666-A). A spark plug with a broken side electrode is not sufficient to check for spark and may lead to incorrect results.
^ Inductive Timing Light (Rotunda 059-00006 or equivalent).
EQUIPMENT (Recommended)
^ DIS Module Tester (DMT) Rotunda 007-00071 or equivalent. This tester contains 12 LEDS, 12 Test Jacks and a built-in interface cable that allows the tester to monitor all DIS module signals.
^ DIS Coil/Sensor Tester (CST) Rotunda 007-00072 or equivalent. This tester is similar to the DIS Module Tester (DMT) except it allows monitoring of signals at the sensor and coils.
^ LED test lamp. A 12 volt test lamp should not be used to test circuit signals. It will load the circuit and may cause erroneous measurements or improper DIS/EEC-IV operation. (ie., engine stall).
NOTES
^ When making measurements on a wiring harness, both a visual inspection and a continuity test should be performed. Inspect the connector pins for damage (corrosion, bent or spread pins, etc.) when directed to remove a connector.
^ Spark timing adjustments are not possible.
^ When making voltage checks a GROUND reading means any value within a range of 0 to 1 volt. Also VBAT readings mean any value that falls within a range of VBAT to 2 volts less than VBAT.
^ When making voltage checks and a reference to ground is made use either the negative battery lead or cast iron on the engine. VBAT means the positive battery cable at the battery.
^ When using the spark plug firing indicator, place the grooved end as close as possible to the plug boot. Very weak flashing may be caused by a fouled plug.