K04 Conversion - Looking for opinions & posting my progress/info about the swap

[ZoliWorks]

Is your throttle body a VDO one? If so, I would swap it for the newer Continental one. I had surging and throttle valve flutter issues with the gen 1 VDO throttle after it was tuned.

Alright I've checked, it is indeed VDO. Do you happen to have a part number for the Continental one, or do they use the same one just different manufacturer/time?

[mjmallia]

I bought a low mile one off eBay for £30.......Continental revised version off a Mk7 GTI or R, as my VDO one was randomly sticking, but smooth on testing.

2018 manufacture year and the P/N is 06F133062T

VCDS to recalibrate it and all has been fine since.

[ZoliWorks]

What were the symptoms of yours when it was sticking, like what did it do exactly? Revs falling slow? Uneven idle? Car randomly dying when coming off-gas? Revs jumping up-down as if it had a vacuum leak?

[mjmallia]

When accelerating it would sometimes feel like the power was being held back for a second and then return, hot or cold.

Boost would suddenly drop on my gauge and return, and felt like something stuck and then suddenly opened......hard to describe.

I could not figure it out and had worked my way round the entire engine......decided to try the newer Conti TB and it resolved all the issues. smooth power delivery and the car also felt more responsive.


100K on the VDO TB and it was an early one too.

[ZoliWorks]

I've definitely had a symptom where it felt like the car would accelerate, then ease off, then accelerate again but not sure if it's my throttle body failing or if it was my broken turbo that underboosted by 0.4 bar and what I felt as a slight hesitation was just the N75 kicking in to compensate.

I haven't felt anything like that on the K04. I'll make a note to replace the TB when all else is taken care of. Currently doing fueling stuff.


Does this look like the correct TB?

https://www.ebay.com/itm/145442141135?epid=1537643366&itmmeta=01HXYPV1EKVXNWD15KA5HTH4EJ&hash=item21dd06f3cf:g:8HoAAOSwuc1lV3CA&itmprp=enc%3AAQAJAAAA4A0C%2BElAklksld8C3r%2F3Pl2HY3SUMEa%2BdfHnfZ2vyd5fNDDajHtLGJJte9EoIwsEdjYy8fVmSTN4BtCXPfq0NXOcdT812Qm5yDgdedNZAAnQldo%2FdoPCLOtib7Fp7kGe7doDw8TWYpm7yHNjsXBjpv6QhaZsoNq2pyXbNDsBwxQN5tYyENhUVBaAyNikwqBWP0Y4bYW2AQwRKmSXS1znEBX9M6FFnfszOlGfbnznkzZTX82RvXTF0WKjDO1sxCGWuswXBZWf8xoRNrokGWNPjBoGvdF7xD20vx5mWX7JL1Ii%7Ctkp%3ABFBMsJfs1u9j

[mjmallia]

That is the one, but does not look in great shape to be honest.

[ZoliWorks]

When accelerating it would sometimes feel like the power was being held back for a second and then return, hot or cold.

Boost would suddenly drop on my gauge and return, and felt like something stuck and then suddenly opened......hard to describe.

I could not figure it out and had worked my way round the entire engine......decided to try the newer Conti TB and it resolved all the issues. smooth power delivery and the car also felt more responsive.


100K on the VDO TB and it was an early one too.

Actually now that I think about it, this is exactly what my 1.4 TSI is doing. Under load, such as when climbing a hill or just driving spiritedly, the car sometimes just lets out a puff and drops power for a second, as if all cylinders would misfire at the same time. I've also had the car die a few times both right after starting or after coming to a stop. At one point it even gave me a fault code for the TB being faulty but I ignored it because it didn't really show any symptoms then.


In other news, I've looked into my fueling issues. The current rail pressure map is stock so it only requests 120-122 bar most of the time but 4th gear and above it requests 130 bar since it also requests 0.1 bar more boost pressure.

I think my FPRV is failing as it might be leaking fuel out of the rail. After letting the car sit for the night, when I open the door, the electric fuel pump kicks in and there's a noise coming from the engine that sounds like you're pumping water out of a syringe but it's half full of air. It also takes a couple of cranks for the engine to start in this scenario. Even if it starts after 3 cranks, it dies right after and has to crank 2 more times till it fully starts up. Tho no issues if I cycle the pump twice, starts right up 2nd crank.


I'll be replacing my fuel pump internals with the VIS motorsport 165 bar internals and I'll be fitting an Audi RS4 FPRV. I'll be doing the valve first to see if it helps with anything or if there's an actual leak somewhere in the system.


While the car drives strong, I feel like it really doesn't like the current setup with cut-back fuel pressure and stock injectors, like it's constantly yearning for more 

[ZoliWorks]

Alright, update time.

I've replaced my FPRV but the issue still persists. However, I revisited an old 2008 thread and realized my memory was slightly off. I was under the impression that you only needed the upgraded pump for 130bar or more pressure and only above 5k rpm. Turns out, you need it for 110bar and anywhere from 3.5k to 5k rpm as the stock pump cant move the required volume of fuel, hence why the fuel cuts. Safe to say my next step is getting some pump internals.

Attached a log where the fuel cuts are visible. Will be back with an update once I've upgraded my pump.




That valve is in quite an annoying spot to reach. Had to cut and weld a wrench for it.