My Accent won't start with a hot engine

I have a mysterious problem with my Accent (2008). It starts perfectly on cold mornings after an overnight sleep but has difficulties on starting after I drive for half an hour or more, stopping and turning off the engine and then trying to start again after a few minutes stop. The starter would sound then stuttering as fighting against a very heavy load, like an electric shaver with a bad battery. Sometimes it won’t spin and I have to wait several nerve wracking minutes or more to be able to start the engine. The car was checked in a certified garage. The electricity is very good and they also replaced the cam sensor with a new one. The car drives better on heavy load etc., but no change on the actual hot-starting problem.
Thanks in advance for any help / suggestions.

This may not apply to your year. I worked on a 1996 Accent with exactly the same problem. It was intermittantly hard to restart after a drive and stop. I rode along until the problem surfaced. The ignition timing was way off on the failed restart (severe kick back). After I connected my timing light, the subsequent crank was without incident; the engine started; and the timing was correct.

I immediately thought of the cam position sensor and crank postion sensor. Since these sensors are Hall Effect sensors, I would have difficulty checking the electronic circuitry. After checking the replacement price for these sensors, I decided to try cleaning their connector plugs. After pulling the plugs apart; cleaning with contact cleaner; and giving a squirt of WD40 to each end, I reassembled them.

The problem has not reappeared.

Hope this gives you some ideas and is helpful