91 Crown Vic stalls when hot

Hi,
My 91 crown victoria stalled today after driving for about an hour. It would crank but refuse to start. After about 5 minutes it started and ran for about 10-15 seconds then stalled again. Just before it stalls it loses power and the engine rpm dies down to zero and it stalls. The temperature gauge was half-way up when it stalled. After the car sits for an hour it works perfectly. The fuel pump is working and delivers 28psi at the injectors. Spark is present right up to the point where the engine stops turning and is also present when it cranks but refuses to start. I read the computer and got one code, code 33. The car has 315,000 km on it and it's a 5.0L EFI engine and a police cruiser. Any suggestions greatly appreciated!
Kenneth

I would look at the temparature sensor to the computer, it may be running but the fuel mix isn't right. The car will run when cold, then stall because of a rich mixture. Also check the EGR valve, it may be letting too much exhaust gas into the engine. You didn't mention whether you had a check engine light?

There is a check engine light but it doesn't come on except when the engine is off and the key is on just like all the other dash lights. Also, which temperature sensor are you referring to? There is a coolant temperature sensor, an ambient temperature sensor, and an air charge temperature sensor according to the service manual.