Does the 2002 regal have a cold motor sensor Car hard to start when cold motor (in the morning )

the idle control motor probly worn-on the throttlbody--also the tps sensor - get intake area inspectd--a haynes manual will xplain complete car-partstore hazit--------starter fluid is used for low compression or weak spark

If your car starts while cold or first thing in the morning etc, only to stall shortly afterwards, and will not start back, but restarts after sitting for some time, your catalytic converter is clogged up, restricting the flow of exhaust gases.

Did you check the fuel pump relay ?
You would need to use a fuel pressure gauge and check pressure before you crank the engine.
When you turn the key switch on, the pump relay is supposed to provide power for 3 seconds to boost fuel pressure.
If fuel pressure is ok, the coolant temp sensor could be telling the computer the engine is warmer than it really is.

Higher cold cranking amp rating on the battery. 850 or higher. Those old Buick motors get heavy in the cold

really need a little more info. but at first thought sounds like either a cold start sensor if equipped. or a coolant temperature sensor. the cold start sensor squirts fuel directly into the intake upon startup wen the vehicle is cold. the coolant temperature sensor adjust fuel air mixtures based on the temp. of the vehicle. when they go bad they go to default which is usually about 175 degrees. so when the car is cold and the faulty sensor tell the computer that the car is 175 degrees when its not then the computer delivers the wrong fuel air mixture, the mixture as needed when its warm when the car is actually cold and needs a different mixture in order to start more easily.

The cold start valve is not operating correctly. Either the engine coolant temperature sensor is bad or the cold start valve itself is bad. You can check the engine coolant temperature sensor by going to radio shack or any electronic store and purchase a 15k ohm or higher resistor. Disconnect the engine coolant temperature sensor (ECTS) harness. Bridge the 2 female spade connections in the harness with the resistor. Start the engine. If the engine starts you need to replace the ECTS. If the engine is still hard to start, you need to remove the cold start valve, (wear safety goggles, and whatever you do don't smoke) place the cold start valve in a glass and have someone crank the engine. You should see gas coming out from the cold start valve. If not take a ohm meter and measure the terminal at the cold start valve after disconnecting the wire harness. The meter should read 25 ohms. If it doesn't replace the cold start valve.

Check the anti freeze level. It is to low the coolant sensor (not the temp. gauge sensor they are to different sensor) can make the computer to thing that the motor is to hot ( after it sits a short time the steam it the motor thinks it hot than what it is) making the fuel to lean. If it set longer but not to cold the sensor is not in the anti-freeze to will think it is colder and put to much fuel in.

It might need a good tune up and the computer scanned as well to see if it hasn't got any cold start trouble code stored in the memory.

I've owned the same car. Check that the fuel relay 'primes' the system before you start the car. When you turn the key to the on position (all you dash lights, ready to start) you should hear the fuel pump run for a second or two. If it doesn't run you can replace the relay for about $30. If the relay is not the problem, it may be a check valve within the fuel line to the engine. This valve keeps fuel from draining back to the tank when the car is sitting. That way, there is fuel close to the motor when it's time to start. The temp senor was not a bad shot, they were thinking it was bad sensor not telling the cold start injector to run. Obviously not the case. However, the injector itself may be faulty in some way. As long as the car always starts, it's one of these problems, assuming the ignition system and engine mechanicals are in running order.  good luck. JK

this is a old model and it should have a cold start valve or it should have a coolant temp sensor, replace the colant temp sensor which is usualy located on the thermostat housing or on the intake manifold and this will sove the clod start problema!!