Ignition System

Electrical resistance increases as the temperature decreases. At the same time, the battery is required to provide more power to operate the starter so the ignition system must be able to deliver a good spark to the cylinder.

Check Secondary Ignition System

1. Install coil primary eyelet connectors per Operation Pride Phase 1, article # 2-02.

NOTE:
Make sure that plug wires are removed by puling on the boot and not the cable.

2. Inspect wires visually. Be on the lookout for cracks, holes, or any damage to the cables or boots. Also check for hardening of the insulator.

3. Ensure that the wires are fully seated on the spark plug and in the distributor and coil. If any are found to be loose, inspect the loose end for any signs of arcing. Also, ensure that the wire terminal, boot, and mating half connector are clean and reassembled properly. Renew the wire if serious corrosion or damage is evident.

4. Using a spray bottle containing water, spray the wires with a mist. Look and listen while the engine is running for any signs of the wires arcing.

5. Attach TestBook with Bear Engine Analyzer to the vehicle.

6. Attach yellow lead to coil wire and plug into the spot where the eight leads for plug wires on Direct Ignition attach. The green trigger lead attaches to the # 1 plug wire. The small wire with the black clip attached to the battery leads must be clipped to the negative terminal of the ignition coil. The cables must be cleaned with brake cleaner for 75 mm on either side of the clip, where the high voltage pick-up and trigger pick-up clip on to the ignition cables.

7. Perform the secondary ignition test for conventional ignition.

The following results will be observed in a good ignition system:

^ Burn Time should be 0.4-2.0 ms
^ Burn KV should be 1.5-2.5 KV
^ Average KV should be 12-17 KV
^ Snap KV should be 17-24 KV

If any of these readings are abnormal, the secondary ignition is~suspect and the following items should be checked:

^ Base timing - The setting should be as specified in the workshop manual.
^ Condition and gap of spark plugs
^ Condition of distributor cap-and rotor (cracks, dirt, carbon brush condition)
^ Resistance of spark plug and coil wires - Resistance should be 3-6.5 K ohms per foot.

NOTE:
These values assume that the fueling condition of the engine is normal.





A high average KV, somewhere around 35 KV (see attached analyzer reading Chart 1) is an indication of an open circuit on that cylinder. Check for an open circuit in the plug wire or poor connections at the spark plug or distributor.

Variables that Raise Average KV are:

^ High Compression
^ Loose connections (spark plug, distributor, and/or coil)
^ Lean Mixture
^ High resistance in a plug wire
^ Carbon brush missing or broken in distributor cap
^ Sudden load on engine
^ Worn spark plug (gap greater than 0.05 in)
^ Retarded ignition timing





A very low average KV, around 2-3 KV (see analyzer reading Chart 2) indicates a short circuit in the plug wire or spark plug. Check for short circuit in the plug wire or ground electrode contacting center electrode of the spark plug. Any wires that are out of the above specification or show signs of arcing must be replaced.

Variables that Lower Average KV are:

^ Low Compression
^ Rich Mixture
^ Small spark plug gap
^ Grounded or fouled plug
^ Advanced timing

Finally, if none of the previous checks has shown a failure in the secondary circuit (damage or high resistance), spray only the wire connections with a fine mist of water. Run the engine at idle and snap the throttle. At the same time listen for any signs of misfire. If there is no misfire, the wires should be considered serviceable.

If misfire is detected, locate the misfiring cylinder and renew the wire to that cylinder. Then recheck for misfire. If the misfire is still apparent, other causes should be investigated (i.e. fueling, injectors, compression, spark plugs, distributor cap & rotor, crankshaft sensor, exhaust leak, etc.).