What controls the 1st and 4th spark?

[dsmdriverjeff]

okay I'm going to sound really stupid and dont judge but what controls the 1st and 4th spark? and.....what exactly is the cas? i thought i knew the answers to all these questions but now i'm doubting myself so I just wanted multiple answers to figure out whats right

Oh and I have a 99' eclipse gsx completely stock

 

[RvlutionMtrsprt]

The left coil pack sends spark to 1 and 4. Ecu drives the coil packs. Cas is a cam angle sensor that senses where the engine is in its rotation.

 

[dsmdriverjeff]

And the cas sends a signal to the ecu telling it when to fire cylinders 1 and 4 right?

 

[MY1GDSM]

If you are not getting spark on 1&4 or 2&3 and the coil test out good, You may want to Test your Power transistor.

I would assume this is why you are asking?

 

[dsmdriverjeff]

I've replaced that twice.... http://www.dsmtuners.com/forums/pacific-northwest-region-dsm/452183-no-spark-1st-4th.html