I have a 1994, Nissan Altima GXE, it has the 2.4L Twin Cam 4 cylinder engine with a standard 5-speed tranny and the car has about 146000 miles on it. I have discovered that my car will not run when the motor gets up to operating temperature. It started when it began to get cold here and snowed for the first time. It wouldn't start at all. I have solved that problem and now that I have, it wont run for longer than 20 minutes. I can start it and not touch a thing, 20 minutes later it is dead. I have sat in it and watched the tach and temp gauges. Nothing out of the ordinary. It is just once it gets warm, which is about 20 minutes after it has been started, it dies. Once it dies, the engine will not start again until it has cooled down again. I am absolutely lost. Any Ideas? Please Help!