Marc780

My 2017 LS460 has the 4.6 L 1UR-FSE V8 and of course that was one of the selling points when I bought it in May. I've noticed some cars nowadays have the fuel system called "direct injection" while other cars have the traditional "port injection" systems. And cars with direct injection, like a lot of VW's for example, have big problems with valve deposits (because fuel does not wash over the valves to provide the cleaning and cooling effects inherent in port injection). And a whole bunch of these engines actually need to have their valves cleaned off periodically (in almost exactly the same way the old-time Model A's needed it done!).

Anyway I discovered the 1UR-FSE engine uses one of each type per cylinder! So this engine use both types of fuel injection systems and every cylinder in the engine uses twofuelinjectors.
My questions are, in your experience do deposits form on the valves? And if you know or suspect that happens, do you do anything special like add a chemical of some kind to the fuel tank?

swfla

iTrader: (1)

Not a concern at all. The port injectors run often enough to prevent buildup. Don't ask when they run as it's computerized and no simple answer.

Striker223

No you will have no issues, the twin injection system is excellent.

sktn77a

iTrader: (2)

As above. The old IS250 had only direct injection and was plagued with issues around carbon/gunk buildup around the valves.

swfla

iTrader: (1)

This is a big reason I won't buy other cars with only DI. Many engines require lots of labor to get to the valves for deep cleaning. There is a solvent cleaner that one can have a shop can run thru but it is preventative maintenance that needs to be done regularly before serious buildup. Easy on a new car, but older cars are typically neglected and require walnut blasting.