On 07/08/2019 at 10:10, Deanmk1vrsoct said:

I've been having very similar issues around the 3-4k rpm mark too. Especially in 3rd and after longer distance runs. Changed nearly everything.

Gonna check this when back off holiday. Fingers crossed.

Best of luck. My exact same fault has returned and it's now on borrowed time, in fact I've pretty much made my mind up its time to move on. 

After taping up the split pipe it ran great, best ever since I've owned it. It then started playing up doing the exact same thing again so I thought the tape bodge may not be quite sealing anymore so bought a new genuine pipe and fitted that....the fault still persisted. 

So off I went again checking over everything I've previously done plus even isolating the servo incase there was in internal fault or a split in the other part of the servo pipe but still it plays up.

I'm convinced there was a hissing noise coming from the DV valve area coming on boost....like it's leaking boost/air, so removed and cleaned out the DV....a new genuine one fitted 20k ago at the start of the fault finding marathon. After re fitting it appeared to run much better and the hissing stopped...bingo...a dirty DV!....er..no...it came back. So, another brand new genuine DV from TPS and the hissing has stopped but the hesitation is still there.

So the only option I feel left is either strip the entire pipework system to look for a leak I really don't think it has or keep playing parts roulette that I'm not convinced will help as I've pretty much changed everything, carried out smoke tests, hooked up 3 different scanners inc vag com and nothing is picked up. Ideally I'd like to fix it before moving it on but if it ends up in a spares or repairs ad then so be it....life's too short and a turboless (and faster) car is calling.

I've never got the 1.8t thing, I bought it as I always fancied one...still do...but I now get how frustrating these cars and other 18t's can be....some appear to work great, others have worse problems than mine, but I feel the conclusion is some will just fight against you with a fault that's impossible to find, like in the loom or ecu itself etc, I guess why so many get broken in the end.

Now I'm no mechanic at all and have very Ltd knowledge on engines.

 

But I stumbled across something saying the vrs used VVT. So I looked up what that was and a google search says .paraphrase to hell... it helps control boost at lower rpm... so it got me thinking, then I found out about vvt solenoids which can sometimes produce hesitation when power is applied under load when going uphill or suddenly increasing power .. 

Can someone with a better understanding of how all this works jump in and clarify whether or not this is even a possibility.

 

It also mentioned that it it usually an electrical problem and not the solenoid themselves. ??

I did wonder but never investigated it....like a fluctuation in timing confusing the system then the boost pulling in and out?....that's pretty much how it feels. The really bizzare bit is I discovered a split in the servo pipe, taped it up, it ran the best it's ever done until it played up again. I replaced the bodge with a new genuine pipe but the fault remained. Same happened with the DV....appeared to be leaking air, removed and cleaned it, ran great again for a couple of days before playing up again, fitted another new genuine DV, fault still remains. It's certainly playing with me but I'm bores of its games now.

I did the whole evap, sai n249 etc delete, catch can blabla. Found a split pipe under the inlet man area. Also replaced injector seals, the breather hose pipe which was falling to pieces too.

I've only drove 20 min home from garage and holy crap its completely different. Instant acceleration with absolutely no hesitation at all

 Feels nice off throttle too, obviously I'm gonna have to wait till I've done more Miles to confirm its fixed permanently but from the small journey I had it is definitely better.

 

http://forums.vwvortex.com/showthread.php?4893472-DIY-Ultimate-SAI-N249-PCV-EVAP-Delete

Cool. 

I found the solution to mine too. Park it for a couple of months and threaten to sell it, then dig it out to use as a stop gap and bingo....running great!...perhaps it just needed a rest, or all the bad weather it's had bestowed on it not being used has taught it a lesson.

If it starts playing up again I'll pull all the front end off it and replace every hose and clip and remove all the junk you have.