A2 1.6 FSI headache

fbi said:
Thanks for the thourough reply, Darko :)
I've been away for the weekend and haven't had a chance so far to have a look at it. Will do it soon.
No chance reaching the sensor plug from below ?
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I don't think you can reach it from below. I would recommend to replace the sensor too, the spot is so tight, it's best to do it while you are fixing the plug.

I wish I have replaced both G62 and G83 when I got the car!
I have no idea what messages those sensors are sending to the ECU, but they must be seriously important, since the engine started to work like a brand new the moment the new sensors were in place. And the air condition works fine too.

Maybe the driver side mirror heating will start working too :D
 
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Thanks !

My car runs just as it did before the fault codes appeared... No misfires, good fuel economy, but as always the last few bhp's seem to be missing, IMO...

I had a look at a tech doc to see the roles of these sensors and the failure strategies.

The N290 valve is only useful in case of hot starts (coolant >110°C and ambient air > 50°c) to prevent vapor being fed to the fuel pump. For a hot start, the N290 closes partly to increase the pressure and condense vapor. The rest of the time, the valve is open.
In case of failure, the valve is it its rest position, i.e. closed.

I have found nothing about the G62, apart that it's used as a secondary data source in the ignition point calculation and the valve timing adjustment.
There's nothing about failure strategy. I bet the G83 input is maybe used instead ?
 
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My little gem is up and running again. . . with a shiny and not to mention working high pressure pump. Thank you a million YorkshireHill/Hilary :)
It was a bit of a pain to swap. (Mostly due to the brake pipe spanner I borrowed from work was a bit large and clumsy in such a small and confined space :p )

Now it runs like it should, and I realize that I never got full power with the old pump.
Almost as if it had ponies under the bonnet instead of horses.

On closer inspection of the old pump I can see several dents inside, close to the bearing, like someone has been using a hammer and a chisel/screwdriver.
There´s also signs of the pump getting dropped onto a hard surface.

The bearing in the new pump is secured by a retaining ring, but in the old pump, the bearing is secured by small dents along the edge of the bearing.
The bearing puller(?) we have at work is broken, so until we get parts for it I won´t be able to get the bearing out.
Hopefully I´ll know more then.

At least the car is up and running. . . . with a mysterious clunking sound coming from the right front spring when I turn the steering wheel. Oh well that´s what tools and spare parts are for I guess :)
 
Back on the road, THS! And more power too! Excellent!
Those damages/dents inside, maybe you could take a photo of them? The difference between the new and the old pump, in how bearing is secured (retaining ring vs small dents) that would be good to see too, if possible.
 
Certainly. Your whish is my command :)

First the "chisel damage"
image.jpg

Then the small dents securing the bearing:
image.jpg
Notice that I managed to pull the bearing out a bit before the puller failed.
 
Thanks! When we meet, the drinks are on me :)

What in a world could chisel it right there? Could it be just a factory 'chiseled' pump that quality control has aproved?
How could that spot cause the pump mulfunction?
 
No idea, but I don't think those dents alone caused it to malfunction. something further in did.
Hopefully it will reveal itself when/if I get it apart.
 
Darko,

I have read all of your threads with the greatest of interest as I have been suffering the same symptons for a while now. Can I just confirm that it was the low pressure fuel pump in the fuel tank that solved your problem?

Many thanks

Ian
 
I too asked this very question #120. See reply on #121.

I'll be going down this route if a MAF and Throttle Body clean doesn't help.
 
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The tank fuel pump replacement eliminated my uphill hasitations and hickups.
I believe that the fuel quality itself plays a part, my experience is that even Shell Power 98 has not the same 'power' on every station.
Since February, I use only Esso 98 Supreme and at the one station only, looks like the engine likes it a lot.

Interesting that Ian's post didn't came as email, while yours Sinless did!?
 
After a long period without any engine light flashing or anything, it turned itself on yesterday for no reason at all, just as I started it at the parking lot!?

I guess the car got a serious shock spending 2 hours in the sun at 21 degrees Celsius :)

Driving a 150 km home was without any symptoms.
 
Fault codes deleted, drove 160 km with no problems, but the engine light turned on after restarting the engine. Another 160 km later was with the engine light on and a few engine light flashings followed by few hesitations on downhill roads!

How far can I drive with this:
17439 - Intake Manifold Tuning Valve (N316) P1031-35-00 Setpoint Not Reached

If this repair requires pulling the engine up, I'd like to drive it down to Germany and have it fixed, that's about 700 km from home.
 
The Vacuum Actuator arm has snapped.
Taking it out was easy, but I have to 'fish' the other part tomorrow and see if there's any chance to fix this.

FullSizeRender - Copy (12).jpg
 
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i drove with snapped arm 5k miles.no problems.after year i fixed and now car have no power under 2k rpm.some cars can beat me on traffic lights what making me angry.probably will need to add some seafoam soon.
 
yovi said:
i drove with snapped arm 5k miles.no problems.after year i fixed and now car have no power under 2k rpm.some cars can beat me on traffic lights what making me angry.probably will need to add some seafoam soon.
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Thanks yovi!

I wonder why this arm breaks right at that spot?
 
Hi it breaks at that point due to the flaps becoming sticky with carbon/gunk as its the smallest cross section. You will find even with a new actuator rod it is impossible to fit without stripping down the inlet tract assembly. I know one member drilled and tapped the two broken parts and then bonded in a piece of threaded rod -so it was then possible to assemble without inlet removal. Cheers mike
 
I saw that thread, Mike! Saves the photos too.

If the flaps are sticky with carbon, they will either stuck or move with difficulties, I understand that.
But it looks to me that it's not the Vacuum Actuator that moves the flaps, but that it just changes the vacuum, depending how much the flaps are open/closed, am I wrong?
When removed, it's easy to see how little power is needed to push the arm up and down.
I think the problem is the type of connection between the Actuator's arm and the drop shaped part under the Potentiometer...
 
NO the actuator operates the flaps--i have seen the tear drop part of the manifold snap, this is not available so you then need a new inlet flap assembly ! so ensure the flaps move freely or you will run into bigger troubles. You could try the spray cleaners through the inlet tract to free them up, but you still need to strip down to fix the new linkage in place. Or try the screw method. cheers mike
 
a2sumo said:
NO the actuator operates the flaps--i have seen the tear drop part of the manifold snap, this is not available so you then need a new inlet flap assembly ! so ensure the flaps move freely or you will run into bigger troubles. You could try the spray cleaners through the inlet tract to free them up, but you still need to strip down to fix the new linkage in place. Or try the screw method. cheers mike
Click to expand...

But what is the Potentiometer's function since it's mounted right on the top of the tear drop part?
 
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