Contour Enthusiasts Group Archives Forums General Troubleshooting Wires on wrong! ...what the heck?

I was making sure my plug wires were on tight today, and I noticed that they were on wrong, no. 3 and 2 were switched.

So I switched 'em back and took it for a spin and it didn't feel any different. Seems very wierd to me.

This is also wierd because I just changed my timing belt, and was very careful to mark 'em and put them back the way they were, I never checked to see if they had originally been on right, so they were either on wrong a long time, or just a few days, but either way it never seemed to drive different.

Is it normal for it to drive fine either way?

Plugs 2 & 3 (as do 1 & 4) fire at the same time. It just so happens that one is on the compression strike and one is on the exhaust stroke, so only one cylinder at a time (4-cylinder) actually has a compustible compressed mixture to burn. Swapping the wires only reversed the polarity of the current through the plugs having no material effect on the spark.

This is called a "waste spark system". Use that for a Google search and you should be able to find more info about it.

Steve

Weird, I've never heard of that but it does make sense. Thanks for explaining it.
-Peter