question

[bamawrx]

Which would be passenger side rear of engine.

[bamawrx]

Wouldn't #2 and #6 fire at same time?

[Dynomite]

Originally Posted by bamawrx

From your photo my car has #6 cylinder wire attached to your #2 label.

Where is the #2 (front first cylinder on passenger side) wire attached?

Firing order is 1-8-4-3-6-5-7-2

[bamawrx]

Disappears deep under plenum. My best guess....the #6 spot.

[bamawrx]

I have no spark on six. Plug is carboned up. Marc suggested to use volt meter to check continuity between wire pairs to rule out bad wire verses pack. I hope its bad wire because I can change it without plenum removal.

[Dynomite]

Change plugs on number 6 plug wire....using good plug. You can change a plug wire without removing plenum??

1 and 6 fire with 1 TDC compression and 6 TDC exhaust.
8 and 5 fire with 8 TDC compression and 5 TDC exhaust.
4 and 7 fire with 4 TDC compression and 7 TDC exhaust.
3 and 2 fire with 3 TDC compression and 2 TDC exhaust.

Then we get to 1 and 6 again but this time 6 is TDC compression.

Drivers side bank from front to rear:
1 3 5 7

Passenger side bank from front to rear:
2 4 6 8

Firing order is 1-8-4-3-6-5-7-2

[bamawrx]

Ok I was right about cylinder numbers. Definitely #6 wire in #2 spot. Any harm in leaving it there?

[Dynomite]

Originally Posted by bamawrx

Ok I was right about cylinder numbers. Definitely #6 wire in #2 spot. Any harm in leaving it there?

I guess not since it is a waste spark ignition.......

[Franke]

I think the story goes that the cylinder under compression would fire and the other one would be wasted spark. Yes - No?

[Dynomite]

Originally Posted by Franke

I think the story goes that the cylinder under compression would fire and the other one would be wasted spark. Yes - No?

Paul wrote a good description...of waste spark.

Originally Posted by Paul Workman

It's called a "waste spark" system. Cylinders are twinned, but only one at a time is in compression cycle when the spark arrives.

Just a point of interest: Because current flows in a loop through the block, coil and plug wires/plugs, the current is the same through both spark gaps. However, due to the much higher compression air pressure in the cylinder about to fire, the gap resistance to flow is much higher, resulting in the heat generated in the spark to be proportionately higher than that in the waste spark cylinder. In other words, the majority of the energy expended in the circuit is concentrated in the compression cylinder, resulting in very little actual "waste", really.

FWIW,

P.