But do they have good continuity?
Use an Ohmmeter and check the resistance between the body and the engine block. It should be 0 or extremely close to it.
Also, how exactly did you check for spark?
The "old man's" way was to take a screwdriver and shove into the spark plug boot while it's not on a spark plug and hold it about an inch away from "ground". You would hear a telltale click, or if done at night a blue to orange spark. depending on how "hot" the ignition is.
By hot I mean by how much voltage is being thrown to the plugs. DO NOT be touching any ground while doing this.. it's not a pleasant experience when 15KV+ goes coursing through your arms. Dunno if this would work on a newer vehicle.
Another note, it's current that kills, not voltage. But it don't take much to do it! Under the right conditions 1/4th of an amp.
Last edited by Isakill; 04-10-2010 at 03:16 PM.