Do direct injection engines almost require fuel system cleaners?

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We know that direct injection designs can allow carbon build up unlike other designs. Does this mean that they should probably have maintenance doses of fuel system cleaners or is there a different way to keep deposits low?
 
My understanding is by definition, fuel doesn't come in contact with the intake valves and so a fuel cleaner would have no effect. With BMW there is a walnut blast procedure to remove the carbon. I think Toyota (or one of the mfg) combines both direct and port fuel injection so that fuel can still clean the intake valves.
 
carbon buildup seems to be an issue on the intake valves and intake ports.

Not sure how you'd get the intake ports cleaned but if you get the valves hot enough they should burn off carbon.
 
My understanding is by definition, fuel doesn't come in contact with the intake valves and so a fuel cleaner would have no effect. With BMW there is a walnut blast procedure to remove the carbon. I think Toyota (or one of the mfg) combines both direct and port fuel injection so that fuel can still clean the intake valves.
True. So maybe some type of intake cleaner fed thru a hose into the plenum or sprayed into the air intake?
 
True. So maybe some type of intake cleaner fed thru a hose into the plenum or sprayed into the air intake?


You're not going to do much good cleaning the rock hard intake valve deposits spraying anything into the intake tract once the deposits have formed. There are dummies on YouTube that make mosquito fogging videos with such method and act like it's the deposits burning when it's actually the spray.
 
You're not going to do much good cleaning the rock hard intake valve deposits spraying anything into the intake tract once the deposits have formed. There are dummies on YouTube that make mosquito fogging videos with such method and act like it's the deposits burning when it's actually the spray.
Any ideas? Direct feed system into plenum?
 
Just a quick thought as I run on by ...

How 'bout a NOS fogger system? Enjoy an extra 50-75 HP RED button boost, and later when you blow the plastic intake off racing a R- spec honda, it will be easy to get to the intake ports
Try that out on your little SUV. A 5 second sedan like the Civic R doesn't need that.
 
We know that direct injection designs can allow carbon build up unlike other designs. Does this mean that they should probably have maintenance doses of fuel system cleaners or is there a different way to keep deposits low?
What deposits are you referring to?
 
My understanding is by definition, fuel doesn't come in contact with the intake valves and so a fuel cleaner would have no effect.
Only way to make contact would be inject early, and use something like Miller cycle. Closing intake late, so you push fuel spray a bit to intake
 
You still have fuel injectors - I use Techron on last tank etc … buy it BOGO - have seen it cure rough idle …
BG has an induction treatment - think you’d need to be on some routine before it bakes on …
Most just wait until there is an issue - then the intake manifold comes off …
 
Knowing that baked on deposits are going to be a problem, has any manufacturer developed an "easy intake valve blasting" engine? Something like an intake manifold held on by zip ties (just kidding).

I know about Toyota's dual injection approach so there's that approach too.
 
Plenty of ways to skin that cat. VW had big problems with their first DI offerings, but worked it out later.
Ford leaves intake valves open for a bit on their DI engines to "backwash" valves. Patented in 1999...

 
Ok, I know I am old school, and do not understand the workings of the modern engines, but can someone explain , in simple terms, what causes carbon to form on the intake valves when, as I understand it, the only thing going past them is clean air on a DI engine. Seems like they are the ones that should never need cleaning. What am I missing?
 
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