A Pause whilst accelerating

Quinnaay · 31 Jan 2018 at 08:17

So I have a problem with my Scirocco 2.0TSI and I'm hoping for a car guru to appear and help me.

Long story short

-Had a problem when accelerating around 4krpm id get a quick sudden pause then it would go again mainly when engine is cold.
-also had a evap fault code arise.
-changed the N80 valve
-changed the maf sensor
- took it for a major service the chap recommended changing the charcoal cannister
-changed charcoal cannister
-fault codes now gone
- acceleration problem still there he then recommended changing the Diverter valve so I did that myselft.
-problem is still there but doesnt seems as frequent.

Any ideas its driving me mad (pun intended)

DereksDontRun · 31 Jan 2018 at 08:56

have some mechanical sympathy and don't boot it when cold

thinking aloud, if its about 4k then is it swapping from closed to open loop control? therefore relying on the map. Is it remapped? Am i right thinking that closed loop looks at the MAF sensor for air going in and the o2/lamda sensor @ exhaust going out, and open loop only looks at the MAF sensor? If so, and you think the MAF sensor is good/clean then could the lamda sensor be the issue? but I'm probably wrong? Sure it's now clear of all error codes?

Armageus · 31 Jan 2018 at 09:00

Do the 2.0TSI's still have PCV issues in the same way the older 2.0TFSI's do? Symptoms include hesitation but also lumpy idle

Drollic · 31 Jan 2018 at 12:19

Faulty injectors - cracked, blocked, leaking etc?

pigeonguyuk · 31 Jan 2018 at 13:26

Clogged fuel filter, failing fuel pump could be cause and engineer struggling to get the correct amount of fuel at the correct time

acemastr · 31 Jan 2018 at 15:18

Why are you accelerating above 4k rpm when the engine is cold?

snips86x · 31 Jan 2018 at 15:20

acemastr said:
Why are you accelerating above 4k rpm when the engine is cold?

^^

GeX · 31 Jan 2018 at 15:54

I've had issues like this on other cars where air leaks on the inlet manifold have caused it. One had a naff aftermarket induction kit that messed up the airflow.

Lordgrayone · 31 Jan 2018 at 16:07

acemastr said:
Why are you accelerating above 4k rpm when the engine is cold?

This, does not help your problem but just stop it

Diddums · 31 Jan 2018 at 16:41

It's a confidence thing. You car's obviously second guessing itself every time you stand on its tail.

Quinnaay · 31 Jan 2018 at 22:37

4k RPM because i live next to the motorway, typically need to get it up to speed when the engine is cold. That combined with noticing this issue i keep wanting to test and figure out an exact point it happens. It does do it warm but not half as much. I think the injectors is next on the list, possibly fuel pump but wouldnt these flag a error code?

@DereksDontRun yes certainly no error code both I and a garage has scanned it, its also not remapped.