A good place to start is replace relay 109 in the third layer of the fuse box, this is the power supply to engine ECU and injectors, these relays do suffer from poor solder joints and can cause poor running and starting issues Use the instructions below to access the relays http://www.fordgalaxy.org.uk/ford/index.php?/topic/8810-relay-30-replacement/&do=findComment&comment=68423