hi all i have an octavia on a 51 plate 1.9tdi

the problem i seem to be having is this, i start up in the morning and it idles fine but when i try to drive i have a loss of power even with foot to floor then wen it gets to exactly 2500 rpm it lurces back to life and will be fine all day as long as its running but if i switch off and restart the problem is back again any ideas would be appreciated

Any fault codes?

For general turbo like problems, the normal culprits apply:

- MAF

- n75

- CTS

- sticky vanes (seems unlikely if you only get this fault once)

- vacuum leak

- MAP

hi ive used a cougar code reader on it but it didnt come up with any fault codes at all

Try running it with the MAF disconnected to start with, and see if the same symptoms occur. It will run with a generic MAF feed. This will however log a fault, which your code reader should detect.

If the car is fine with the MAF disconnected that is your probably the first thing to look at changing.

You could remove the vacuum pipe from the n75 to the actuator on the turbo and see if you get a nice smooth movement on the control arm when a vacuum is applied. You might need to get under the car to do this, and remove the under-engine try if fitted.

How many miles has the car done? When was it last serviced / age of air filter?

From cold the glow plugs kick in at 2,500rpm to help running, could this be a problem with the electronics, CTS perhaps or 109 relay or glowplug relay.

I would find someone with VCDS and get car checked for faults again. Some bogo OBD scanners don't pick up all fault codes.

hi all just to let you know it was indeed the maf sensor unplugged it and car run like a dream thanks for your help everyone