I have an Audi A4 1.8 SE year 2000 and am having problems with it not starting . it will start for 2 weeks then start playing up and not starting no matter what the weather is like or if the engine is cold or hot ! . when the AA checked the fault it has no spark at the spark plugs but it does have power to the fuel injectors , they recomended that i change the camshaft sensor and then the main relay !
i have changed the camshaft sensor but this has now made the car worse and now it will not start everyday .
can someone tell me what the main relay is or maybe the correct name !!!!

thanks in advance