w140 coupe 500 playing up

[smoothcoupe]

hi guys,, i have a august 1993 coupe 500 with 120,000 miles.. in the past year i have spent a fortune on it. ie new maf, new eta(throttle actuator), new fuel pumps/ filter, new cats, all the above were fitted as a result of gradual power loss and eventually non starting.. it was sent to a spaecialist and 2 main dealers who were telling me to change various items, most of the above... then a friend of mine who had a similar problem with his bmw m5 said he would put his money on the cats so i then replaced them and hey presto the car started and ran great, up until i got banned from driving ( speeding in the beast 127mph on m1) 18 months ban and £650 fine,, not recommended.. hence the car has been stood for 9 months.. now the car starts up fine and runs for about half an hour then dies, then when trying to resart it turns eagerly but back fires, then when left for an hour starts again.. any ideas guys, as i just got my wife insured on the car.. cheers guys

 

[grober]

Lambda sensor/s problem ?? Sounds a bit as if its a fueling problem but I'm just guessing from the symptoms??