The old man went out in his 3 door the other day and on acceleration around 3-4000rpm the engine keeps cutting out and the engine management light comes on. If you turn the ignition off and restart the engine the light goes out and resets itself but as soon as you accelerate again the fault re occurs. The engine hasnt long been rebuilt so he is just trying to run it in ready for a set up.
can anyone help? thanks kyle

 

Fastest way is to get the codes read. You would need a Led- or Star-tester.
It's normal that all errors reset when you turn the ignition off. So, connect tester, do a run and read the fault code(s).