Poor Performance With Full Tank

[Radders1004]

Hi,

I have a bit of a strange problem, I have a 2007 2.2 D4d Carolla verso, 75k miles.

Recently after brimming the tank the cars performance is down above 2.5k revs, the car struggles to find power. Once the tank drops to about three quarters full the performance returns. This has happened 5 times now, all after filling the car up.

A few days ago the car would not rev above 2k revs when half full and after a seeing the post for cleaning the EGR valve thought this may be my problem. I cleaned the valve and the cars performance returned until filling up again and the same sympoms as before have returned.

Could it be fuel tank breather related, anybody know how to get to it or where it is? I am struggling to find a reason this is happening, I know I am due the 80K service soon and the fuel filter will be changed but if this was blocked it would show all the time, not just with a full tank of fuel.

Any ideas anyone before I let the dealer have a look?