Recently I have been experiencing pining from my engine despite the fact that it?s not overheating etc. Sometime ago I replaced the timing belt and after I noticed that the engine would not rev out when stationary, however, it does so when driven. It should be noted that prior to changing the belt it would rev out when stationary. In addition, it shows no sign that the valve timing might be incorrectly set as it starts very easily etc. Any opinions, suggestion and views on how I can resolve this problem will be greatly appreciated.