That sounds like a failing fuel pump relay, good until it overheats or fails, then ok after it cools. A bad fuel pump will do the same thing but check the relay first, it is the easier and cheaper option to go to first
Check your fuel filter and pressure.
why is my 1995 buick roadmaster running hot
Fuel pump is gping out it may have enough fuel to start then it works like a vacuum but the pressure is not enough to keep it going. Same thing happend to my Buick Lasabre.
There are several reasons that can cause your 1995 Buick Century to quit running. The most common reason is a lack of fuel. A bad fuel pump can cause the engine to quit running.
It's probably the fuel pressure regulator.
It sounds like the Throttle Position Sensor needs replaced.
If no light illuminated first step check fuel pressure
why is buick lasebre running hot
Bugatti Buick
The fuel pressure for a 2003 Buick LeSabre typically ranges from 41 to 47 psi (pounds per square inch) when the engine is running. It's important to check the specifications in the vehicle's service manual or consult a professional mechanic for the most accurate information. Proper fuel pressure is crucial for optimal engine performance and fuel efficiency.
The low side AC pressure for a 1988 Buick Reatta typically ranges between 25 to 35 psi when the system is running at normal operating conditions. It's important to check this pressure with the system fully charged and while the vehicle is idling. Always refer to the vehicle's service manual for the most accurate specifications.
Especially if you are in cold areas, it takes more pressure to circulate cold oil. When it warms up, the oil flows easier through the system reducing pressure.