F.I. Cleaner Worthless on Direct Injection?

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I have a Infiniti M56x (Q70 5.6 V8) with a Direct Injection System and from everything I have read online a quality fuel injection cleaner that you pour in the tank won't do much in comparison to a regular fuel injector system. Inputs?
 
Don't see why not. Its access to the injectors is the same. It wont have access to, and so can't clean, the inlet tract, but that's not its primary role anyway.

Maybe, because DI injectors see higher temperatures, they suffer from baked-on deposits that are harder to shift?
 
It should clean the fuel path, but the concern with DI is the pvc deposits on the intake valve. Pour in solvents won't clean that unless its a hybrid design with a cold start enrichment injector up stream of the valve.
 
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Find one with PEA like CRC,Gumout All in One, or Redline SI 1. PEA will survive the heat and help. CRCGDI IV and Gumout DI cleaner make a aerosol can that you spray into throttle to get the top side deposits. These products have PEA in them also.
 
Originally Posted By: spasm3
It should clean the fuel path, but the concern with DI is the pvc deposits on the intake valve. Pour in solvents won't clean that unless its a hybrid design with a cold start enrichment injector up stream of the valve.


There are claims that certain additives will survive the combustion process.

Im not 110% sure I believe that. "surviving" means that that a hydrocarbon will be in existence in the exhaust and pcv stream. HC in the exhaust is a no-no from emissions (granted the cat will consume it).
 
Originally Posted By: JHZR2
Originally Posted By: spasm3
It should clean the fuel path, but the concern with DI is the pvc deposits on the intake valve. Pour in solvents won't clean that unless its a hybrid design with a cold start enrichment injector up stream of the valve.


There are claims that certain additives will survive the combustion process.

Im not 110% sure I believe that. "surviving" means that that a hydrocarbon will be in existence in the exhaust and pcv stream. HC in the exhaust is a no-no from emissions (granted the cat will consume it).


I agree and even if they survive the combustion process how will they have significant contact with the back side of the intake valve and stem?

If there was a lot of camshaft overlap, i could see those products cleaning the intake valve underside.
But camshaft overlap and emissions don't go together.
 
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Originally Posted By: spasm3
It should clean the fuel path, but the concern with DI is the pvc deposits on the intake valve. Pour in solvents won't clean that unless its a hybrid design with a cold start enrichment injector up stream of the valve.


I don't buy it's all the PCV deposits. Those that install catch cans on VW's, for example still have tons of deposits. Other engines like Hyundai, GM, and Ford have little deposits. It's all the design of the engine and maybe the PCV system.
 
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