Direct Injection Problems

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Originally Posted By: wemay
Originally Posted By: Trav
If it was that simple you would think it would be OE on every DI engine. It would surely be cheaper than the warranty claims. Just playing devils advocate.


I agree, catch-cans, separators etc. will only make it easier to void your warranty. They also haven't proven to be effective. If ithey were, they would be OE


Times a dozen! Way over rated on effectiveness. And already present on many cars right in the valve cover, just a bit simpler.

Virtually every car ever made with a dry intake design is full of oil. Doesn't seem to hurt all of them...
 
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I have yet to clean the valves on my 145k Mazdaspeed 3 and it still runs strong with no CELs.
 
Thank you all for the many views and responses.

It seems that DI can be relatively trouble free, and the preferred maintenance routine is an occasional Italian tune up.

Ecotourist
 
My best friend has a first year IS350 with about 120k around town and track miles. He has had no issues other than poor quality rubber and trim.

We are in south Florida which accelerates rubber and trim weathering.

He also has the direct w/ secondary port injection.
 
Originally Posted By: badtlc
Does the lexus have the hybrid DI setup?


On the 350 yea they have the dual injectors (1 DI and 1 Port injection). The 250 only has DI the last I saw.

My SiL has a IS350c. When I change the oil I get the engine up to temp and floor it to get the Port injectors to open up and "wash" the intake valves.
 
Originally Posted By: Jimzz
Originally Posted By: badtlc
Does the lexus have the hybrid DI setup?


On the 350 yea they have the dual injectors (1 DI and 1 Port injection). The 250 only has DI the last I saw.

My SiL has a IS350c. When I change the oil I get the engine up to temp and floor it to get the Port injectors to open up and "wash" the intake valves.


The port injectors are only supposed to operate at low throttle, low rpms, typically when going slowly. Unless they went different than other hybrid DI engines coming out.

If you want to use the port injectors, just idling would be the easiest way. The DI injectors are there to produce the power.
 
Originally Posted By: badtlc
Originally Posted By: Jimzz
Originally Posted By: badtlc
Does the lexus have the hybrid DI setup?


On the 350 yea they have the dual injectors (1 DI and 1 Port injection). The 250 only has DI the last I saw.

My SiL has a IS350c. When I change the oil I get the engine up to temp and floor it to get the Port injectors to open up and "wash" the intake valves.


The port injectors are only supposed to operate at low throttle, low rpms, typically when going slowly. Unless they went different than other hybrid DI engines coming out.

If you want to use the port injectors, just idling would be the easiest way. The DI injectors are there to produce the power.


Its a mix of them opening. The Port injectors open when cold to create a lean condition to warm faster. The D/I fires also to control it with retarded timing.

The port injectors also open up on low speed but med-heavy loads.

Its actually a really good design and interesting. Here's more on it...
http://www.mr2.com/files/mr2/techinfo/Random FSM Data/2grfseen.pdf
 
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Toyota specifically stated long ago that the extra injector is for part throttle cylinder filling issues.

It was NOT put there to clean anything...
 
Originally Posted By: SteveSRT8
Toyota specifically stated long ago that the extra injector is for part throttle cylinder filling issues.

It was NOT put there to clean anything...


But if the effect is that it cleans the valves, does the intent matter?
 
Originally Posted By: Mykl
Originally Posted By: SteveSRT8
Toyota specifically stated long ago that the extra injector is for part throttle cylinder filling issues.

It was NOT put there to clean anything...


But if the effect is that it cleans the valves, does the intent matter?


Yes. Correct info matters.

It is only an issue because people use it to imagine that Toyota was somehow prescient about DI issues when they were not.
 
Originally Posted By: SteveSRT8
Yes. Correct info matters.

It is only an issue because people use it to imagine that Toyota was somehow prescient about DI issues when they were not.


So then I'll say this as a bystander to your disagreement who doesn't know the truth either way regarding Toyota's intent.

It's your word against his. I don't know which of you is correct because no references have been provided by anybody.
 
Originally Posted By: Mykl
Originally Posted By: SteveSRT8
Toyota specifically stated long ago that the extra injector is for part throttle cylinder filling issues.

It was NOT put there to clean anything...


But if the effect is that it cleans the valves, does the intent matter?


Maybe if that effect was known. At this point, there is no evidence it provides any cleaning and since Toyota said it wasn't there for cleaning, why do people assume it will clean?
 
Originally Posted By: badtlc

Maybe if that effect was known. At this point, there is no evidence it provides any cleaning and since Toyota said it wasn't there for cleaning, why do people assume it will clean?


I believe that the assumption comes from the fact that with port fuel injection the fuel washes over the valves and prevents carbon from sticking to them.

If this extra injector being added is basically just another port fuel injector, throwing in fuel somewhere in the intake manifold, this seems like a fair assumption to make.
 
Originally Posted By: Mykl
Originally Posted By: badtlc

Maybe if that effect was known. At this point, there is no evidence it provides any cleaning and since Toyota said it wasn't there for cleaning, why do people assume it will clean?


I believe that the assumption comes from the fact that with port fuel injection the fuel washes over the valves and prevents carbon from sticking to them.

If this extra injector being added is basically just another port fuel injector, throwing in fuel somewhere in the intake manifold, this seems like a fair assumption to make.


As assumption is an assumption. I'd assume that if it was going to prevent issues or solve a problem, Toyota would advertise that to set itself apart.
 
Originally Posted By: badtlc
As assumption is an assumption. I'd assume that if it was going to prevent issues or solve a problem, Toyota would advertise that to set itself apart.


Call Toyota's marketing department and see what they have to say.
 
Originally Posted By: Mykl
Originally Posted By: SteveSRT8
Yes. Correct info matters.

It is only an issue because people use it to imagine that Toyota was somehow prescient about DI issues when they were not.


So then I'll say this as a bystander to your disagreement who doesn't know the truth either way regarding Toyota's intent.

It's your word against his. I don't know which of you is correct because no references have been provided by anybody.


People within the automotive industry have spoken at length about DI engines and their part throttle issues with uneven cylinder filling. It's a well known problem, and the extra injector is a band aid solution.

Please note I have no disagreement with anyone. This is not secret or anything. Its been published as well, so anyone who looks around a bit can satisfy their curiosity
 
Originally Posted By: SteveSRT8
People within the automotive industry have spoken at length about DI engines and their part throttle issues with uneven cylinder filling. It's a well known problem, and the extra injector is a band aid solution.

Please note I have no disagreement with anyone. This is not secret or anything. Its been published as well, so anyone who looks around a bit can satisfy their curiosity


Well yeah, but the same can be said regarding DI engines and intake valve deposits, which is at least a well known problem among enthusiasts; I can't imagine the engineers aren't aware of the issue.
 
Well seeing that many with the 250 have had carbon issues while the 350 has not, seems pretty clear even if it was not intended for that function, the Port Injectors do offer a cleaning of the intake valve.

Its one of the reasons I recommended the 350 over the 250 when my SiL was shopping for cars.
 
But you guys talk like everyone has these issues when they don't.

This is far from universal, GM has had the 3.6 DI motor out since May of 06, and they do not have any issues with valves carboning up excessively. Neither do many other engines with DI.

The most ridiculous assumption is the one that somehow concludes that the extra injector is the sole reason the 350 does not have carbon issues. Data please, or something other than just a guess or a Toyota commercial...
 
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