# Direct injection vs Port Injection



## captainhero17 (Apr 10, 2018)

Youtube videos and many people got me confused.

Question
Are 2.0TFSI TT MK3 engines:
A) direct injection
Or 
B)Port injection?

(Many people say that direct injection was for USA markets while European market has Port Injection)

Which is it?


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## RobinHelsby (Mar 24, 2018)

captainhero17 said:


> Youtube videos and many people got me confused.
> 
> Question
> Are 2.0TFSI TT MK3 engines:
> ...


Does this help?
https://www.audi-technology-portal.de/e ... -principle


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## 90TJM (Sep 30, 2013)

Direct, but on EU models I think there is also an auxillary port injector to keep the valves clean.


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## captainhero17 (Apr 10, 2018)

RobinHelsby said:


> captainhero17 said:
> 
> 
> > Youtube videos and many people got me confused.
> ...


It explains the mechanics of TFSI very nicely! And acc to it TFSI is Direct injection.

However, most people (US drivers AdiWorld and in any VW or Audi Youtube video) complain that they have direct injection in USA while europe gets Port Injection. So in theory, European market port injection has less problems with carbon buildup.


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## captainhero17 (Apr 10, 2018)

90TJM said:


> Direct, but on EU models I think there is also an auxillary port injector to keep the valves clean.


I cant find answers in any tech specification lists. But most USA VW drivers complained how "good we have it" in Europe due to not having direct but port injection. And how we dont have to deal with almost mandatory carbon cleaning of engine every 30.000miles.

Thats what confused me.

HumbleMechanic and Engineering Explained did videos on carbon cleaning and port vs direct. And mentioned possible market differences.

(Same how Samsung sells their Galaxy phones with 2 differences CPU manufacturers for US market vs European market)


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## captainhero17 (Apr 10, 2018)

I guess no one has any idea about this.

Because it is confusing and not unheard of that a manufacturer has different systems/features and solutions for different markets.


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## chelspeed (May 6, 2017)

captainhero17 said:


> I guess no one has any idea about this.


Surely if you're that interested you can take the engine cover off and trace the fuel lines and see if they lead to injectors in the head or in the inlet manifold. I'd look on mine but everything is out of sight under that cover and I don't care enough to remove it to look.


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## captainhero17 (Apr 10, 2018)

Im not that knowledgeable to know what to look for or at. 

I was hoping someone here knows.


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## kevin#34 (Jan 8, 2019)

it should have both, direct and port injection


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## chelspeed (May 6, 2017)

captainhero17 said:


> Im not that knowledgeable to know what to look for or at.


Fair enough.

If you want to know a bit more than look at the pictures on the second post for direct injection engine. The cutaway of the cylinders shows the injector (the cylinder spraying the green petrol in) located close to the cylinder head. That means the fuel rail (long green pipe on the other drawing each feeding four injectors, there are two on the drawing as it's a V8, one on our engines with 4 or 5 injectors) will be located close or over the cylinder head.

On a port injection engine the injectors and their fuel rail will be arranged over the inlet manifold. The inlet manifold is the collection of around 50mm dia pipes that link the air filter to the engine. There will be a big common pipe from the air filter that feeds a manifold that has 50mm pipes connected to each cylinder along the engine. About 25mm before the manifold enters the cylinder block you will see injectors pushed into bushes on the top of each pipe. The injectors will be linked by a fuel rail similar to the one on the direct injection engine.

Picture of a direct injection TTRS engine here https://www.bar-tek-tuning.com/2-5l-tfs ... p-reliable The inlet manifold is the black tubular bit on the front with the four rings and TFSI cast into it. The injector ports are the holes under the manifold pointing into the cylinder head, the injectors will fit into these with a fuel rail along the top. As others have said there may well be other injector(s) into the manifold for port injection.


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## macaddict111 (Jun 13, 2018)

Audi doesn't really care about keeping your intake valve clean. You should never have an issue with that unless you granny the car and never let it fully warm up or drive it over 3k RPM, lots of threads on that. Everyone has direct injection, modern engines and their performance/emissions rely on it. The US has DI only. European markets (and elsewhere) also have port injectors, which have a fuel rail that attaches to the low pressure line before the high-pressure pump. I believe it's to comply with WLPT (it helps emissions in certain driving scenarios like low-power cruise, as port injection has less challenges with fuel/air mixture). I'm sure it also in theory "helps" with intake valve coking, but it doesn't mean more performance potential or anything.


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## captainhero17 (Apr 10, 2018)

I didnt know that Audi does hybrid system (like how Toyota has both Port and Direct). Interesting!

I did grandmother it. Since I mainly drive in heavy city centre traffic with minimal movement. (especially now that major road works are occurring and diverting additional pressure on other roads)

I am afraid yet curious to see the amount of carbon in the engine though


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## powerplay (Feb 8, 2008)

This was interesting and apparently the TTRS 2.5 is both direct and port injected.


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## captainhero17 (Apr 10, 2018)

Interesting.
Stands to reason that 2.0tfsi is the same.


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## macaddict111 (Jun 13, 2018)

captainhero17 said:


> Interesting.
> Stands to reason that 2.0tfsi is the same.


It is, you can see the blank for where the port injectors should be (on US models) in the intake manifold runner (four little blank holes right where the manifold curves into the engine block).


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## captainhero17 (Apr 10, 2018)

macaddict111 said:


> captainhero17 said:
> 
> 
> > Interesting.
> ...


Still amazing how US market was screwed over for once in comparison to the Europe. Its usually the other way around. No ide why US doesnt get this too. Thats basically VW asking you to carbon clean every 30.000miles.


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## cliveju (Jun 27, 2018)

This is relevant:

http://r-techperformance.co.uk/2-0-tfsi-tuning/


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## kevin#34 (Jan 8, 2019)

I believe is more relevant this:

https://www.dropbox.com/s/9liqv8ll6dhqg ... 1.pdf?dl=0


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## spidey3 (Aug 13, 2019)

I just verified looking at the service manuals. The TT RS has dual injection (low pressure into the manifold and high pressure directly into each cylinder), both in Europe and in the USA.

The 2.0 engines in the US only have the direct injection.

Yet one more reason why I'm glad I forked over the additional $15k for the RS...


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## captainhero17 (Apr 10, 2018)

Audi is not very transparent with how they divide markets or the differences.
I mainly asked about this because my car has been acting up lately. Mainly to do with the gas delivery and the gas pedal feel. (makes me feel like the car will stall and the gas pedal is wobbling more than I remember).

The car did 52900miles and quite few of those are in slow standstill traffic. So carbon buildup is possible.

VW suggested fuel additive for 10eur (90ml). Just wanted to educate myself on how carbon buildup occurs in 2.0 TFSI engines. As many said its notorious for carbon buildup.

Wanted to try VW fuel additive before I fork up 50eur for seafoam treatment (or worse 400 eur for wallnut blast clean).


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