Carbonation problem

[jasonlee471]

I've had porter kit carbonating in my keg for two weeks which is the time the instructions told me to
Leave it in there for but as I have mentioned somewhere else it hasn't quite carbonated right and for some reason is pouring exactly like Guinness with a creamy head but even less carbonation so it's verging on flat.
How can I change this, is it just a sign it's still carbonating and needs more time or can I add more sugar to try and get it going again?

Also I was listening to a podcast about carbonation and they never mentioned that you could add sugar to a keg, can you?

 

[Leon103]

Did you add sugar to the keg? If not then it won't carbonate, it needs sugar for secondary fermentation. You can open the keg and add sugar now.

Did you put Vaseline on all th seals?

 

[jasonlee471]

Yeah sorry should have mentioned I did everything like normal, added the priming sugar.
I've just tasted it again two weeks after it should have been carbonated and it's still the same and the creamy head tastes really....weird with a taste which is probably really obvious to everyone else but I don't know how to describe it. My first kit tasted similar and I thought it was a vinegar taste but maybe it's yeast :s

 

[Kman]

Vinegar is a sign of infection

 

[jasonlee471]

Vinegar is a sign of infection

Yeah I found that out and assumed the last batch was infected but this sounds stupid but i realised the taste wasn't vinegar, it's a strong taste that I assume many people can identify straight away but I just can't put it into words

 

[Kman]

Just leave for a week then try another, some beers need time to come good