problem starting espace

hi there i am trying this as a last resort before putting a hammer through car can anyone please help,
I have a renault espace quadra txe 1990 was running fine untill about a month ago and now refuses to start i have tried a number of things eg. plugs, leads , injectors ,thermoatat sensor,and map sensor but still will not start turns ok wants to fire but will not keep running any ideas gratefully received,