hi i had a problem last year i filled the car up the night before to go on holiday and it would not start the next i worked in the motor trade for a few years and found that when you turn the ignition on you shoul hear the pump in the fuel tank starting up it is pushing fuel to the front of the engine. any way after i got back from mt hols i investigated further it was the low presuure pump in the fuel tank a common problem which i was going to do mysely but as it was full of fuel i did not want to risk spilling it all over the drive so i took it to my local citroen garage and was charged about 150 pound which was not that bad concidering the pump is about 120 pound you can do it yourself its not hard but unlike other cars there is no inspection flap under the back seats on a picasso so the tank has to be dropped you should join the picasso owners club its free and has forums that helped me in the past
regards
robin sutherland, September 2009