well now that its hot out my 240 will not go after about 45 minutes of driving. it acts as if the throttles not working. if you keep pumping the gas nothing happens. you have to turn the car off and then it will go again if im lucky an sweet talk it. could this be a mear vacuum leak or is it something else. it makes a spiting sound some when you give it gas during this problem. but runs like a champ when i go to work in the morning, only a reving idle for about 30 seconds. any ideas? ive replaced the amm, cleaned the throttle body, air control valve, adjusted the throttle valve switch, and changed the plugs all within the last month. HELP.

 

How does the speed sensor and engine harness look?
How long does it happen for?
Is the fuel pump relay ever been changed?