Reddavey

My 2007 GV keeps going into Limp mode after starting and sometimes while driving. Up until recently I have beenable to reset it by turning the ignition on and off over again a number of times but this has now stopped working and has also gone into limp while driving. The not so local Chrysler garage has diagnosed it with a fuel rail/ high pressure fuel line or diesel filter fault but the guy at the garage sounded less than convinced so I expect I have wasted another £110 diagnosis fee! Does anyone have any suggestions? Sometimes it works fine, sometimes it doesn't, more often now it doesn't. Engine Management light is on. I put small amount of petrol in it a year ago but diluted it straight away... I also noticed a partly melted wire beside the airfilter (coming from the fuel sensor collection of wires - now insulated) Help!