1.6 Petrol (AVU) Rev Problem Limiting to 5k RPM

[reliantreviver]

Currently have a fault with our Octavia that has left me scratching my head.

Symptoms

In gear or in neutral the car will not rev past 5k. It is hitting some form of imposed limiter and "bouncing" rather than a misfire or such. 

Engine check light came on recently.

 

Initial investigations found a split intake / breather pipe. But replacing this has made no difference.

Unlpugging the MAF did appear to allow the car to rev past 5k. But I have now replaced it with a new budget pattern part and the fault persists. Unplugging it makes no difference either now, so not sure if I imagined it previously?!

Replaced both coolant temp senders incase the ECU was imposing a safe "cold engine" limit - if that even is a thing?

 

VCDS lite is returning no recorded fault codes.

 

Thoughts, suggestions?

[BrownBarge]

Crank sensor

[reliantreviver]

Still not gotten to the bottom of this.

 

Changed the CAS as suggested. Seemed to make no difference. Although the fault was not present on the second run out, but then returned after that, with it now very occasionally running ok and pulling to the red line, but generally same as before. I did note that the sensor removed was filthy with oil, and there is a slight leak on the gearbox. But given that these sensor are not optical I doubt it could make much difference being a bit oily?

One other point to note is that the idle is very erratic on start up, which I believe to be a bit more of a common thing from reading around.

 

Any further suggestions would be greatly appreciated if you don't mind me picking ya brains....

Edited 26 June, 2015 by reliantreviver