Chiefy

Heya all, Been reading these forums for a while now, and thought it might be an idea to put my problems down here. I own an '06 berlingo 1.6 16v, and ever since day one, have been having problems with it. 1) fuel enconmy is absolutly terrible. I'm lucky if I get 27mpg out of it. And that is at an average of 70mph... 2) I have to go up any hill I come to in 1st gear. Why? Because only 1/3 of the accelerator pedal does anything to the engine, the other 2/3rds is dead. Now, I hope this isn't normal :P , at least other cars I've owned haven't done this. I've taken it back to Citroen 4 times now in the last 2 months, who have said each time 'There's nothing wrong with your car because there is no fault codes on the ECU'. :D So guys, I was wondering, has anyone here got any ideas as to being able to rectify the problems? Cheers in advance all Nick