I recently purchased an 2001 Q45t. When I got the car it would crank over but wouldn’t start, security light stayed on solid so I had a new key made and programmed and it fixed it. After the car was running It was idling rough so I ran codes and had to replace knock sensors. Precious owner has just replaced fuel pump, fuel filter, and spark plugs. After letting the car sit for a couple of days I go to start it and it’s just cranking over but not starting again, the security light goes off like normal, it’s getting spark, the fuel pump is kicking on.I had the guy that made the key come look at it and he said everything was fine. Checked all fuses, and I just replaced crank position sensor thinking maybe that’s the problem but it didn’t help a thing. Any suggestions as to what’s going on?