1993 240 Wagon, 250,000 miles

Need help with diagnosing both issues listed below. May be separate issues or may be related.

Issue#1: Sometimes the car won't start in the morning. The engine will crank over; however, I have to depress the gas pedal all the way to the floor and hold it there before the engine fires and sputters to life. After a few seconds of sputtering, it runs fine all day. This seems to happen only after the car has been sitting (like overnight, etc.); normally doesn't happen during the day when stopping at the store and starting the engine up.

Issue#2: The other day, while waiting at a red light with my foot on the brake pedal, the engine stopped running. Just completely stopped. I started the engine back up and the light turned green and I drove away fine. Weird.

Two or three years ago, I replaced the air mass meter and crank position sensor. That's about all I've had to do to the car other than tires, brakes, etc. I need help with where to start diagnosing the issues described above.

Thanks,
Cabbie