My Sonata is very hard to start especially after I have driven it that day. It cranks maybe 5 times in the morning to start. but after that it requires many (maybe 15-20) cranks to start. Next day, same problem all over again. Seems to start better from a cold start than from a warm start! Car runs perfectly after it starts??? Any suggestions?
Start off by saying more about the car - esp mileage & maintenance history. E.g. when is the last time (if ever) its gotten new plugs/wires, air filter, fuel filter? Note anything remarkable - e.g. does it crank poorly? Do you smell fuel? Does it smoke momentarily on hit/warm start up? Stuff like that. If the maintenance is not up to date, make it so and then see what happens.
I got the car when I started med school in 2004. It has 68 thousand miles. I faithfully get the oil and air filters changed, but being severly broke, in debt and over worked, and new twins at the table 
I have not maintained the car beyond the oil and filter. I drive in heavy traffic. I’ve never smelled gas etc and it crankes strong. My question,
if I have to piece meal the maintenance (small budget), what should I start with?
Pull out the owner’s manual, look at the maintenance schedule, and find anything that hasn’t been done. Get in touch with a reputable (ask around), independent (non-corporate chain) mechanic, and ask them for an itemized estimate for all of the work, and recommended priorities. Include this restart problem.
I would start with the fuel filter, plugs & wires. A new fuel filter is not expensive at all. Is this a 6 cylinder? If so, the plugs & wires probably won’t be expensive nor cheap. Figure a couple hundred bucks or less including the new fuel filter (as long as it isn’t inside the gad tank). If it is a 4 cylinder, you can easily do the plugs & wires yourself for around $40-50 if you’re not afraid to get your hands dirty & just learn some basics. People here can tell you how to go about it.
It is quite possible that neither of these things will address your problem, but these basics are a) always the best place to start & b) good as general maintenance anyway. You should just do it - trying to save money by putting off basic maintenance items is one of those things that is penny wise & pound foolish.
Work on figuring out the basic maintenance. And, the next time the car won’t start, hold the gas pedal to the floor while you turn the key to start & just let up if it fires. If you get that to work a few times (once or twice can be coincidence) report that back.
Is your check engine light on?
Thanks!
No check engine lights come on.
I’ll get some help on the plugs and wires (it’s a 6).
Not sure if the filter is in the tank or not, but I’ll cross that one when I get there.
Thanks again
So I guess that the engine turns for about a second and then starts when cold and cranks for five seconds and then starts when hot. I may say what sounds like wrong advice now but: Have you tried pushing the gas pedal down about an inch when you try to start it? If the car starts better you might have a problem with the idle control motor (a thing that positions the throttle). You can live with that. If you had the money, I would say to get the car to the shop to get your codes looked at and then to get the car fixed. Some auto parts places with or without the repair facility will read the codes for free. Write the codes down for reference here in addition to what the person tells you.
Spark plugs may do it. The mileage is high enough for the fuel filter change if the plugs don’t bring a better start.
If the fuel injectors are leaking into the intake, that could flood the engine. To un-flood the engine, hold the gas pedal to the floor while you crank the engine; as (if) the engine starts, ease up on the gas.
Let us know results.
I suspect the idle control valve which sets the conditions for cold start and then after the coolant warms the motor changes the air fuel mixture to accomodate. the coolant temp sensor at the base of the radiator may be bad, not the sensor that sends the temp signal to the gauges.