vans?

I own 1.9 1999 renault trafic diesal.It was working ok then on m25 slowed down no revs,managed to adjust the cold start setting on pump and got home almost on tickover.On the dash i have had light for a few months goes on and off telling me serv.The throttle cable is fine.Also there has been fuel dripping from bottom of pump but have not been able to trace it.