My wife's 2005 Corolla has appx. 45000 mi on it. It started and ran fine in the morning. Late afternoon when she went to start it, it would not start. I tried starting it and it would turn but not catch. I finally got it to catch it would run for about 3 secs then stall. The only way to get it to stay running is to hold the throttle at 3000+ rpms. If you lift off the throttle it will stall. The gas is at half tank and on level surface. Any ideas???