Engine shut off



I have a 1993 Pontiac Grand Am with 64,000 miles. When I drive it around the city, mostly under 50mph, it runs perfectly, although a little rough. But when I drive longer distances ( for more than an hour) at higher speeds, and then reduce the speed for example when I approach a toll booth, the car starts to shake and the engine shuts off. After a while, it starts again. It is happening now more frequently, at least twice during a 2 hour trip.

I have taken it to the mechanic several times and he has replaced the motor mount, replaced oxygen sensor and performed other maintenance jobs. I even left the car with him several days so he would drive it around, but he has not noticed anything. Probably he has not run it for an hour at high speed in the highway.

I desperately need my car and cannot afford to buy a new car now; but I do not want to spend a great deal of money on a 1993 car either.

PLEASE, PLEASE, HELP ME OUT!!! Can you give me (and my mechanic, of course) some direction?

Mil gracias (Thanks a lot)



Check the Mass Airflow Sensor. My cougar was doing that, I replaced it. And it fixed that problem.


The lock-up torque convertor is not dis-engaging after driving at highway speeds.

Is this what’s happening? Drive at highway speeds for awhile, exit and as soon as you come to a stop the engine stalls. It resarts and dies right away. This happens a number of times until it finally starts and stays running.