you need to check the car out when it is acting up. Unless the vehicle stores a code, the only way to find the problem is to have it happen and test to see what the car is missing at the time. Fuel, spark, injector pulse... Some times an evap
valve stuck open can cause a no start or long crank. But don't replace parts by just guessing. It gets expensive and you will probably replace a lot of parts you won't need. Wish I could be more help but if the car runs normally everything will probably show up as normal.