hi, i have a fiesta 1.4 petrol(2004) and it has developed an a anoying problem, while driving it has an intermitting problem of pulling back as if it was running short of petrol, then it will suddenly shoot forward, somtimes it has got so slow that i have had to pull over wait for a while and restart, i have had it to the garage several times with no joy. so far it has been on the dynostics m/ch no fault found, fuel cleaned out and new fuel filter, renewed core plugs, checked for water leaking onto electrics water-washer ect, new ht leads,air filter, oil and filter, tried leaving fuel filler cap slack as there is a vacume build up, sometimes it does seem to run ok, but when i do get the pulling back fault things i have noticed it does nt matter on the weather dry or wet, seems to happen when fuel is low ie 1st to 2nd mark, i,m starting to wonder if it could be a faulty fuel pump? but i have spent so much now i just want it fixxed. can anyone help ?/ many thanks, alan