What are some of the side affects of a coil that is on its way out, (but not 100% dead?).

My car runs rough and then stalls after start up and i suspect its the coil.

any ideas?

I could be this ... driving along and the car stalls on you ... los of power due to dirty spark ... engine chugging.

And then when it is dead ... the starter cranks ... but you get nothing.

try measuring the resistance...

do yourself a favour and go and buy a gregories manual.

already have, the resistance on both the primary and secondary are out.

Remember with a coil you either have spark or no spark.Thats the most logical explaination.I havent seen a coil just slowly die.For example with the i6 falcon from eb to el the coils usually stop working do to small cracks along the edge of the coil on the side with the screw holes.Water or even condensation builds up and get in and burns out the coil.Also leads can destroy your coil,cause by crossfire.This can be seen with powdery leads greyish colour.