k reg Micra K11 ticks over but no power?

I was driving along the road at about 45mph and my car suddenly lost all power. It ticks over fine but when you try to rev it gives you very very little. If I try to drive it just kangeroos. I have changed the leads-dont work. The dissy cap was changed not long back.
I put on new throttle body dont work.
I am going to change the petrol filter but not conident it will do anything.Any ideas on what is causing this or how I might diagose the fault will be appreciated.

graham
January 2010