ORenson

Hello
my tachometer didn't move when I last started my C4; only after a minute or so, it jumped on but didn't go fluent but jerky (not sure this is the right word). The more I drove, the smoother/reactive it was getting again. So I thought I would be a one time thing but just started the car again with the same problem.
Anybody some good advise?
thx for helping me out.