Bit of an odd one, Driving along no issues at all, give it some hammer and when it reaches 5000rpm it pulls the timing back as if its detected knock but overcomes it quite easilly and revs no issue to the red line.

Now if I reset the ecu it wont do it for maybe 10 tanks of fuel, very intermitant, this last time it hasnt done it for 4 months ? Anyone ever come across this issue before as I'm a bit puzzled.

No abnormal oil consumption or coolant issues to report, Starts and runs fine. no extra mods on the engine so that rules that out.

Not sure why when the ecu is reset it's fine for ages ??

Plugs showing signs of packing in they've done 30,000 on 16% meths ?