Q: Crank everytime but won't start

My E500 Crank but won't start I diagnosed it and I got code was P0141 and P0140, which I learn quickly it has nothing to do with the crankshaft no start, in November the car stall took it to Mercedes Benz they said it was the crankshaft position sensor they replaced it and it work, January it died again I took it to Mercedes Benz they said it the fuel pump labor and part was too expensive so I DIY I bought a fuel pump from ebay replace it and it work right away, now we are in March the CEL Came on before I could scan it it died, upon my research I learnt the 02 sensor has nothing to do with crank no start, battery is new crankshaft position sensor is new , fuel pump clicks when the key is turn. What could possiblybe the problem, I also replace it idle puller in February.

PS :before the CEL Came on i have been idling my car 12 hours a day so I could sleep after work due to be being homeless

My car has 220000 miles.
My car has an automatic transmission.