[Skools Out]

actually it could still be your oil injection it may have some missing teeth on the gear and not be oiling proper and it could be making your motor run hot which would cause the pistons to swell and get tight in the cylinders which would make it run sluggish *and would make the compression start to fall as to also getting the block hot gets the electronics on the motor hot too which could inturn hurt them. may want to try putting some oil in the gas and run it some with both oil injection and mixed if the problem goes away with the oil added to the gas you'll know your oil injection isn't working correctly.