In the morning, all the metal parts in your car are literally smaller, because as science tells us, things shrink in the cold and expand in the heat. Some metal components in your ignition system, being colder, and thus smaller, are now farther apart. So it takes more electrical potential (voltage) to jump these larger gaps. So everything from your battery to your starter motor to your spark plugs are using more energy to get you going. Add to all this the fact that your oil is much thicker when it's cold, and tends to act more like pancake syrup than a lubricant, which your engine has to work harder to pump.
It could be a number of things....if the distributer has a hair line crack it could be drawing moisture over night.
Getting a new battery with more cranking amps or taking your starter apart and cleaning it might solve the problem.
A car may start better in the afternoon, because the heat of the sun has warmed up the engine. Once a car has sat over night, it may be difficult to start in the morning because the engine is cold.
condensation
The cold weather makes it harder for the battery to provide amperage to start the car.
glow plugs
There could be many reasons why a car has an issue starting in the morning but not the afternoon. The most common start is that the battery has an issue with cold start, and would need to be replaced with a battery that does have a cold start option.
I would get in my other car
check the fuel pump relay. it may be overheating.
the coolant temperature sensor could be faulty.......
Leaving the car stereo on overnight can drain the battery and make the car impossible to start in the morning.
There could be many reasons why a car won't start in the morning. It might be a problem with a cold start, but it could be the battery isn't connected all the way, or the lack of gas.
Jump start car and ensure alternator and battery are good.
It would be difficult to succeed as a car rental company in Chicago. This is because of the number of existing large firms.