it would prob do both TBH.
If you got a bailey one it should be fine.. there is lots of things that could be wrong with yours.. dizzy timing cam timing air leaks incorectly adjusted idle valve. throttle position sensor...
prob worth checking the TPS first to be honest... open the bonnet without the engine running.. pull the accelerator cable/bracker thing towards you.. you should hear a quiet 'click' almost as soon as you pull it. if you dont the TPS is nackered and is likely to be your problem. (TSP is the black thing on the right of the inlet manifold)
cheeRS
Phil