How do you know when you need new coils??
 

My ls1 z28 is running poorly. i don't think its running at its full potential.. when im slighly on the gas it kinda deccelerates right on the 2500rpm line on every gear? what can this be?

Lots of things.

Plugs, wires, fuel filter, air filter, bad tune, injectors, MAP sensor, MAF sensor, etc.

Coils rarely die but it can happen. But they usually either work or they don't so you would have a constant misfire. Coils should be one of the last things you check though as they are made to last and have no moving parts.

Scan the car for codes and start there.

Then clean the MAF sensor with spray cleaner (especially if you have a K&N style filter).

Next would be fuel filter and run a bottle of good injector cleaner through the car. Next up is check/replace plugs and wires. A small crack in a plug or burn in a wire could cause a misfire.

Is your car misfiring or just hesitating?

The more details or even a video might be helpful.

Thanks i'll try posting a video up tomorrow.. but its not misfiring it just really hesitates... my wild guess would be something to do with my MAF sensor or Fuel

Coils typically work or don't work. There really isnt any on between.