My 2006 Altima 2.5 4cl has startup issues. Only when engine is cold. Warm and hot startups are no problem. Spent hundreds on multiple diagnosis and still no valid solution. On cold car either takes multiple attempts to start or doesn't start at all. When checking spark plugs. They seem to be covered in fuel and flooded out. Once you clean them the car starts fine. Drives smoothly, no issues after its started. Had crank shaft sensor replaced. Have ecu reprogrammed and updated. No mechanical issues after multiple tests. Only issue is cold starts. Becomes a super hassle and is scary to log out because I don't know if my car will start back up. Please help!