Seafoam fuel treatment instead?
All direct injection gasoline engines have this problem.I'm curious about the cause of the build-up. Didi they tell you anything about what caused it to be needed?
Because the fuel is injected directly into the combustion chambers, and NOT into the intake.
The fuel, therefore does not wash the back of the valves so they build up with carbon.
Some manufacturers recommend walnut shell blasting as maintenance.. which in some cases requires cylinder head removal.
One manufacturer has added a single injector in the intake specifically to try keep the valves clean.
summary.. fuel additives won't work. If they did.. the fuel itself would do the job.
IMO, Direct iniection gas engines suck because of this design problem.
Correct. I have yet to investigate how this is done with a motor where you don't have controll of the throttle.You would have to have the means of revving the engine while stationary, probably with commands through the OBDII port. It's something that I don't know how to do.
If it were me, I'd have the dealer do the deed
Advanced scan tools allow direct throttle control but I haven't had time to see if this option is there for the Voltec drivetrain.