Ford Repair: 2001 Ford Focus, ford focus zx3, powertrain control module

Question
i recently purchased a 2001 ford focus zx3 from a local used car dealer. on my way home, the heater hose busted and the car ran hot for about 2 minutes. i fixed the problem and it runs fine now, however, when i accellerate and shift (its a 5 speed), when the rpm's go over 4000, the car looses all horsepower, up till 4000 it runs fine but when it reaches 4000 it just stops accellerating. i think it might be something with the computer but i dont have a lot of money to pay a shop to try and diagnose it. please please help me, i would greatly appreciate it. thank you sincerely.
Joshua Whitworth

Answer
Without testing the vehicle, I would have to guess that you are engaging the engine rpm/speed limiting functions of the Powertrain Control Module.  The PCM has programming that is designed to protect the drivetrain, and limit the vehicle's top speed.  You can also engage the rpm limiter by racing the engine while the vehicle is not moving, and in neutral (customers come in occasionally, concerned with the odd sound that the engine makes when this is happening).  This vehicle's OBDII Powertrain Control System would turn on the Emissions Light if any of the sensors are out of their normal operating range.

I hope this helps,
Dave