Cutting out hot or cold engine

this has just happened this morning , on pulling up to stop at a juction my engine cuts out and wont idle! it has been fine and was services about 3 months ago , only other problem i have had with the engine is , when it starts in the morning it idles slow , then as the engine temp rises to normal so does the rpms , the engine ticks over at 12,000 rmp i tried to ater the throttle cable ajust but this make no difference i have checked the throttle body for leaks , new gaskets have been fitted , i was wondering if this could be a MAF sensor problem ? or throttle sensor ???