No carbonation

[steturbo]

I have done my 1st barrel of cider and 1st barrel of lager, I have primed them both exactly like the the instructions say and they have not carbonated, I have also injected 1 8mg Co2 bulb into the lager and it's still flat and they both are cloudy, I barrelled the larger 4 weeks ago and cider 3 weeks ago, they both fire out of the barrel and they both have a head that lasts for a minute or 2, can these be saved or do I need to poor away? It would be a shame because they taste nice but just flat and cloudy, I'm thinking of priming them both again but I'm unsure if this will work, please help