I read about injector cleaner post in this forum and solstice forum previous days.
Now I use GA-01. LNF system is direct injector, so I do not care about injector, I care about deposit will adhere on cylinder valves and cylinder head.
FX, TPI or TBI system injected gas to intake then mixing gas through intake to intake valves. that mean gas wash valve , port, intake line etc.
On the other hand, direct injector inject gas to cylinder directly, this gas cannot wash anywhere.
Moreover "revive" will occur and deposit back to valves when plugs was ignited gas.
If you had experience oil change your self, you can see so dirty oil. why?
Because of the high dependence on oil wash direct injector.
This is bad google translate from wikipedia.
Deposition of the soot in a combustion chamber
Compared with a port injection type engine, in a cylinder, gasoline burns and dregs accumulate in many cases.
When it is easy to generate soot in the super-lean burn exceeding 40:1 and the soot adheres to an injector nozzle, it is the main causes that proper fuel injection becomes impossible.
Furthermore, compared with a port injection type, control of fuel injection is severe, and if fuel oil consumption is out of order, the vicious circle of becoming further easy to generate soot will occur.
Deposition of the soot in an air intake system
the combustion gas by the side of an air intake -- blowing (it mainly generates at the time of overlap) -- carbon accumulates between manifold ? air intake valves.
with the usual port injection engine, it is based on overlap -- blowing -- etc. -- the injected fuel flushes carbon deposited between manifold ? air intake valves, and it inhales together with fuel-air mixture, and burns.
However, since the air intake valve of a direct-injection engine passes only along air, it does not have fundamentally that the dirt which adhered from the manifold before the valve comes off.
Although the detergent action between the air intake manifold ? valves stated with a fuel additive or high-octane gasoline is also a direct-injection engine therefore, it is meaningless.
For this reason, it is easier to deposit carbon on an air intake system, carbon adheres to the valve for whirlpool generation, a valve breaks down, since a required whirlpool does not occur, fuel is not well mixed with air, but abnormal combustion is caused or there is also an example which a spark plug smolders and falls into an engine malfunction.
Moreover, a hit of a valve and a valve seat worsens and the trouble which occurs by combustion chambers, such as an extreme power down, not being sealed may also arise.
Aggravation of combustion stability
If soot adheres in a combustion chamber, the evaporation speed of fuel will be out of order.
It is the bottom of black smoke unstable [ an engine failure and an idling ] as main condition, and unusual, an unstable engine sound, the fall of an output, and the wrong of fuel consumption, etc.
Although it decreased with a new style engine that those condition appears by optimization of a combustion chamber configuration, improvement of an injector, the advancement of feedback control, etc. with the piston top, a question still remains in durability, reliability, and maintenance nature rather.
For example, even if it has adopted direct injection in the model, there are usually an example which serves as port injection by the vehicles (police vehicles etc.) of the special use, and an example from which model て which has adopted direct injection in Japan also serves as port injection for overseas.
It seems that such a change is mainly made on maintenance nature and the emission gas standard of the destination.
Furthermore, it is better to shorten an oil change cycle compared with a port injection type, since a part of this soot remains in a combustion chamber, they are collected by engine oil and oil dirt is intense.
since there was actually no addition of a detergent additive (soot etc. are microatomized) those days in which the GDI engine appeared as the present oil, this amount of combination was mainly increased -- "-- the so-called oil " only for a GDI engine was used as pure oil for GDI vehicles of Mitsubishi.
The poor business performance in which the scandal of this problem and Mitsubishi originates became the cause of making the project which uses GDI as the prime engine suffering a setback.
In the oil (more than SJ) of the standard generally sold now, even if it uses which oil, it is almost satisfactory, but there is no change in it being better to shorten an oil change cycle slightly too.