A LOOK AT IGNITION SYSTEMS
Remember when standard ignition with points, condenser and low kv coils was the going thing? Then came (HEI) high energy ignition, Was this a big change, No more holding to the spark plug wires, to see if the coil was firing. The technicians was in for some training. With a little schooling and some experience this was not so bad. There was a pick-up coil, signal converter, ignition coil distributor cap, rotor, Ignition wires and spark plugs. Now look at what is here! (DIS) Distributorless Ignition System (C3I) Computer Controlled Coil (DIS) Direct Ignition System (IDI) Integrated direct Ignition (EDIS) Electronic Direct Ignition System (EI) OBD II (96 and up) These are controlled differently on the primary and does not effect the secondary in the scope analysis. DIS IS IT The Direct Ignition System has a crank/cam sensor, This reference signals the ignition module the primary current is controlled by the module, much like HEI, But there is a coil pack one coil for each two cylinders. Each coil drives one plug positive and the other negative, the two spark plugs fire simultaneously. Where does the spark go? Since current takes the line of less resiances and the coils are stacked on the ignition module, if a opening occurs in the path of secondary current, it can short through the module to ground and this is not good. Never removing spark plug wires to check for spark or power kill, use a suitable tool to do this or there could be damage done to the coil and module. Note: You can use a spark tester and a short ignition cable to check the kv of the coils. I like the adjustable Spark tester, it can be adjusted to the proper kv for each coil. By Carlis B. Wilson Email:
