My wife has been driving my car for the past few weeks. I'm not blaming her I'm just saying that up front because I can't tell you "how" the car was driving prior to it not starting. She said a week ago that the car was getting hard to start. She said it was reluctant to start on the first try but would fire up on the 2nd. Yesterday she called me and said she couldn't get the car to start. It turns over fine, tries to start sometimes but never fires up. I thought it might be the fuel filter so I replaced it and still have the same problem. It has half a tank of gas. Checked the battery and cleaned the posts, no change. I pulled the ECU cover and all the connections are solid. Visually inspected the fuses, all seem to be fine. I thought maybe it could maybe be the plugs or fuel pump. I can't hear the fuel pump, but never remember hearing it in the past either. Haven't checked the plugs yet, have Denso Iridium, 1 heat range colder, could they foul from my wife putting around for a few weeks? Any suggestions?