In heroics i do less than 3k dps and i dont know why. I use spell roation of flame shock lava burst then lighting until flame shock timer damage runs out then flame shock again.
my gear and talent set up is here http://www.wowarmory.com/character-s...n=Gastraphetes please any suggestions would be very helpful
Heroics are a horrible indication of your DPS, because none of the fights last long enough to matter.
That being said, your gear is all over the place. You shouldn't be gemming spell pen (useless for PvE), and you need to get rid of your two mana trinkets for something useful. Like Abyssal Rune or Nevermelting Ice Crystal. You shouldn't be having mana issues at all.
Same with the intellect gems, get rid of them for more spellpower.