Ideally, replace the cable with a brand new one as they are not very expensive.
Alternatively, lubricate it with oil. You can do this by undoing the end in the engine bay and dripping oil in that end while holding it up and working the inner cable in and out. You can make up a kind of funnel with blue-tack or plasticine if needs be.
Cables sometimes get hot where they pass by a hot exhaust and dry out. Also make sure there are no tight turns or kinks in the run of the cable.
Finally, ensure that the accelerator pedal moves freely by lubricating that at its pivot.
ChicksFan, November 2011
