Chrysler Repair: CAR DIES WHOLE DRIVING/Starts after 1/2 hour, crankshaft position sensor, cam shaft

Question
2000 PONTAIC GRAND AM
HAD A TUNE UP AND OIL CHANGE DONE  WEEK LATER DRIVING CAR AT 75 MPH CAR JUST LOSES POWER DROPS TO 50 MPH AND STOPS, WILL START BUT NOT TURN OVER 3 ATTEMPTS.. HALF HOUR LATER OR SO STARTS UP WITH A KICK..
CAR TOWED, FUEL INJECTOR CLEANED.. FOLLOWING WEEK CAR CHECKED AGAIN FOR TUNE UP.. PLUGS CHECKED ETC ALL WAS OK ACCORDING TO THE MECHANIC.. ONE WEEK LATER AGAIN 75 MPH GOES DOWN TO 50 MPH WHILE FOOT PRESSED DOWN ON GAS PEDAL.. STOPS.. ATTEMPT TO START IT WILL TRY TO START AND DIE.. AFTER ABOUT A HALF HOUR IT WILL TURN OVER WITH A KICK..
WHAT COULD THE PROBLEM BE??  

Answer
Hi Cassi,
This behavior has ignition system sensor written all over it. These sensors detect the position of the rotating parts of the engine and time the spark and fuel injection pulses accordingly. They are solid-state electrical crystals which fail in this manner of breaking down when they get warm, only to recover at cooldown. I am not familiar with the engines that might be in your Pontiac so I can't be specific as to where to look for them, but the chances are good it is the crankshaft position sensor, with a secondary possibility of the cam shaft sensor being the problem. It is an external device that can be changed in a few minutes in most cases and costs around $50. You can verify which it is by going to an Autozone Parts store where they will often due a free readout for fault codes stored in the engine controller, two of which will be specific for the crank and the cam sensors. Then you will know which to replace.
Roland