A few additional comments on my injectors plugging post, as well fuel cleaning solvent being an apparent fix for another frequent 928 problem...faulty fuel gauge.

The addition of injector cleaner and MysteryOil to my tank and by keeping the tank topped off, seems to have helped solve another problem I have been living with, an eratic to often non-functional fuel gauge. It appears the float system likes to be cleaned with the fuel cleaner also. It is now back in operation and is again going all the way up reading full. It was sticking on 1/2 full and sometimes wasn't even responding before adding these additives. I think it has helped to keep the tank full for a few days and allowing the upper part of fuel level readout system in the tank to remain in contact with solvent.

The injector system is still partially plugging once in awhile, but it clears itself out fairly rapidiy and the injectors are seating. They are no longer flooding the engine when shut off and the engine is running much better. I think I will only use the premium clear AMOCO fuel from now on.