why is my car over revving?

I have a chevrolet Tacuma and just had a new timing belt fitted it is now over revving sometimes on breaking any ideas on how to fix.
George, April 2012


done
My citreon saxo 1.4 car is over reving but only some of the time not always and also under revs and cuts out why is the cause for both of these thx

tina windsor, May 2012
check all your air pipes are put back right on the trunking and servo hope this helps

raza newport, April 2012
link Click here to see other fixes for Chevrolet.