1.2 RT fuel injection problem?

Hi everyone, my problem occurs after the car has not been used for 24 hours. It will turn over but not fire. After constant turning over it finaly begins to fire on one or two cylinders the picks up and runs [If the battery lasts long enough anyway]. Once started the car runs fine and will continue to do so all day. It is not electrical as I have removed the plugs and they are bone dry. My knowledge of fuel injection is very limited but it seems to me, I beleive the fuel line stays pressurised, so I am thinking a possible fuel pump/valve problem.
Any ideas
merryknees