I have a chrysler voyager 2.0litre petrol manual 5 speed 97 which will not start i have checked for spark and petrol petrol comes through fine but when i checked for spark i have spark at 3 and 4 plugs but 1 has no spark 2 has a very weak spark it was running fine until one day i went to it and it hasnt started since engine cranks over great just will not start up please can u help