this is from race logic site, they cut one injector at a time and cycle them to make sure there is no damage to one given cyclinder. this proves that banging the limiter with fuel cut is bad. it is also proven that fuel cut is not instant, on datalogs on various cars showing that the revs still went over there limit. however spark cut is instant and there is always fuel there to keep things cool.
Cutting a single injector pulse
The idea of cutting fuel to an engine sets alarm bells ringing in engine builders, as they all know that running a lean combustion mode will elevate in-cylinder temperatures very rapidly. The denser the air/fuel charge, the more heat the lean burn can generate. Therefore it is vital that a fuel cut system will not cause a lean burn.
Racelogic Traction Control prevents lean burn by removing 100% of the pulsed fuel delivery – essentially the affected cylinder takes a gulp of fresh air; the in-cylinder temperature remains virtually unaffected.
Prolonged fuel cut on one particular cylinder would cause scavenging of the petrol lining the inlet tracts, and when the next full fuel pulse arrived, it would be partially reduced in quantity by the re-wetting of these tracts. RL Traction Control rotates cylinder cutting to prevent this situation from occurring