Starting problem when hot, also irregular engine performance

My wife's 2004 Ford Escape XLS, 3.0L, automatic trans, 2wd, with remote start, has had a starting problem since it had 30k miles or a little less on it. The problem is more prominent when the ambient temperatures are 80+ degrees, however I have had the same problem at slightly lower temperatures. When making short trips, 1-5 miles, turning the vehicle off, restarting and making another short trip the darn thing will start and then die. Sometimes 2 or 3 short trips are fine, sometimes not. It used to take about 1 hour before the vehicle would run properly but the last time, after 3 hours, I finally made it to where she was, started the car, had to pressure on the accelerator to keep it running and keep the accelerator down slightly when stopping to keep it running until we got home which was about 10 miles. When we got home, it restarted fine!

The car now has 68k miles on it. When the car had 30k miles on it, I took it to the dealer to have the problem solved before warranty expired. Of course, they could not find a problem.

Recently, my wife called the dealer and they said "bring it in, we will not leave you hanging since you brought it in before the warranty expired." Well, they anylized the car and said that it needed an Idle Air Control Valve. They wanted to charge her to replace it. I will leave that part out. I just replaced the IACV and the problem has not been resolved. Another thing that I noticed is at 4000 RPMs, the engine acts like it is hitting a rev limiter. A co-worker said his father-in-law has a Taurus doing both of the same things.

We are going to keep each other aware of possible repairs and results.

Has anyone heard of or experienced these problems? If so, what was done to resolve them?

My Dad has a Windstar that was not starting when hot. He replaced the EGR valve and the sensor related/attached to it and it solved his problem. I do not want to buy every sensor under the hood until I find the one that fixes the problem, I can not afford to. Thanks for any help.