FSI manifold flaps : how much travel ?

fbi

fbi

Member
Hi,
I have the fairly common 17439 error code. ("Intake Manifold Tuning Valve (N316): Setpoint Not Reached")

The plastic rod isn't broken. I can see it moving when the revs go up as it should.
But mys question is : how much is the travel of this rod supposed to be ?
Mine goes, say 5mm up. It that all ?

Thanks in advance :)
Fabrice
 
fbi said:
No FSI owner can answer this ?
Click to expand...


It is strange that nobody replied !!!

This thread seems to have slipped through the cracks.

I am sure that you will get a response soon.

Had it been a tdi question I would have jumped in and tried to help, but with the FSI my knowledge is limited and so I prefer to leave it to the guys who can give you some facts rather than assumptions.

I am sure you will get a response now that the thread has had a "bump".

Steve B
 
Thanks Steve,
I've no doubt that you would have helped :)

This is a very common FSI issue... Several owners over here have already fixed that themseleves, hence my question.
 
Hi I have recently had to resolve this very issue. I didn't carry out the repair but I did supply a clean inlet runner and vacuum actuator to replace my sticky and broken actuator. I'm having an educated guess in 10-15 MM travel at the actuator (stroke).
If your certain your actuator is attached still (they always break at the far end AFAIK) I would say your best bet is to run some of the cleaner through the air intake and try to free the flaps up.
Hope that helps cheers Mike
 
Should the actuator move at all revs? Like if you just give it a small blip? Or is it only at higher revs?
 
The total stroke of the vacuum actuating unit is approximately 15mm. The actual operating range is however slightly less and is further reduced if the manifold ports are gummed up which is always the case to some degree. It is this gumming that causes the flaps to become sticky which invariably leads to a broken vacuum unit shaft.

We have carried out this repair multiple times and always ultrasonically clean both the upper and lower manifolds prior to re-assembly. The actuator switches (opens wider) at 2800 revs when in motion and can sometimes be felt by a little "prod" in the back. Good practice is to refurbish the injectors when the manifolds are off and the notorious coolant transfer pipe is also very accessible at this stage.

blue skies
tony
 
Not an easy anwer, the flaps are closed depends on the engine load and rpm.

Instratified charge mode, the intake manifold flap closes the lowerduct in thecylinder head. The intake air flows at a faster rate and tumbles intothe cylinders via the upper duct.


InHomogeneous lean charge mode,as in stratified charge mode, the throttle valve is opened as far aspossible and the intake manifold flap is closed.


InHomogeneous charge mode,the intake manifold flap is opened or closed dependingon the operating point.

  • In the medium engine load and speed ranges, the intake manifold flap is closed. As a result, the intake air tumbles into the cylinder, thus improving mixture formation.
  • As engine load and speed increases, the air mass that can only be induced via the upper duct would no longer be sufficient. The lower duct of the intake manifold flap then opens in addition.


FSI.JPG

http://www.volkspage.net/technik/ssp/ssp/SSP_253.pdf
 
Last edited:
Thank you all for your replies. So that confirms my guess, the stroke is reduced...
The observed stroke of approx 5mm is after having sprayed a full can of cleaner through the inlet. I doubt that spraying a second one will improve things much further...
The rod is not broken, I can se it attached to the "elbow" at the manifod side, and see that moving.
 
Sorry to dig up an old thread but I'm still slightly confused, I'm still trying to sort the old 17439 fault.

Should I be able to see the actuator rod move when revved?

The rod is not snapped and moves fairly well if you move it manually but no movement with revs?

What controls that?

Cheers in advance


Sent from my iPad using Tapatalk
 
It's vacuum controlled so you need a good throttle opening to see it move. Or it can be operated via vagcom. The problem with blipping the throttle is you see the rod move but you need to be sure it's attached to the flap mechanism as the rod breaks at the far end.
If it is still attached it may be possible to ungum the flaps with one on the inlet cleaning sprays. Cheers Mike
 
Thanks for that Mike that makes a bit more sense.

The rod is still attached at the bottom, but I have it some pretty good revs and no moving?

I sprayed the moving part with a little WD40 and put 1/2 a can of inlet cleaner through and then drove 15 miles to work and she was the best she has ever been ran like a dream no flat spots or hesitations just spot on.

Drove home still pretty good and then this morning, started her and she spluttered and stalled and then started and back to the normal slight hesitation and slight flat spots.....

I wonder if the vacuum isn't strong enough or its slightly sticky?

I will cure this problem as I love this A2 and I have sorted everything else out and just this last problem


Sent from my iPad using Tapatalk
 
Hi,
I am having the same problem and found out that the cam has broken off the end of the inle manifold.
IMG_0571.jpg
I have contacted the local Audi dealer and they are quoting £409 supply only for the loweer manifold.
Is this part uneque to the A2 fsi or can it be got from another car?
 
There are other specialists but A2 cars fixed mine and gave me the very detailed explanation that Tony gives above. Having scrutinised his bill, he also seems to put very little margin on parts. I am a proud man and a keen home mechanic but when someone can get parts much cheaper than you, why not invest in his expertise in fitting them as well?
 
I just paid 240GBP for the lower manifold at the German A2 clubdealer.

She is running fine again.

Verstuurd vanaf mijn Nexus 5
 
I had mine done at 4rings in Dartford cost me around £750 at the time not sure if it's gone down now though
 
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