Put car in garage for heater plugs relay. When I got it out after leaving it sitting for about an hour, started car and about 5 seconds later it died had to turn engine for about 2 mins before it started. Put back into garage they put one way flow fuel filters next to injectors. Got it out after lying cold for an hour it wouldn't start at all. AA boy told me I needed my injectors overhauled garage then tells me it is my fuel pump. Can anyone shed some light on this.