Once the engine gets up to temperature, when changing from 4th to 5th, the power & revs drop for a few seconds then picks up again - almost as if going into safe mode but then allows full power - happens multiple times over a trip
Temp reading spikes to around 70'c for a second then drops to just below 60'c immediately
Had Fuel filter changed ; tank cleaned; sensors changed etc
Any ideas, could it be the EPU?