Hyundai Repair: Wont Start When Hot, coolant temperature sensor, spark plug wires

Question
2002 Hyundai Accent 1.6 MT.  It's been about 2 months now that I have had this issue.  In the mornings it starts right up.  If I let it sit for over and hour too.  But a quick stop like to the grocery store or to get gas and it cranks but will not start. Thinking it was the starter I tried another starter and had the same issue.  I did a radiator flush, replaced the Engine Coolant Temperature Sensor, changed out the Thermostat and Radiator Cap.  I still have the same problem.  My question is should my next step be to replace the Crank Sensor?  It's a $57.00 part and it looks quite difficult to replace.  I could not fit a socket and ratchet to remove.  What would be the best way to replace?

Answer
Hi, Senoel.  The crank sensor is held in place with one 10mm bolt.  To replace it, you'll need a swivel 10mm socket, a long extension, and a ratchet.  

Even though the crank sensor could be causing this issue, I'm leary of having you replace this part.  As you've found out, it can be quite expensive to guess at which part to replace.  I've a few questions and procedures for you which will hopefully help us determine the type of problem.  For example, #3 below may help determine whether the crank sensor is the cause.  If the crank sensor is not functioning, you will get no spark.

1.  When the engine will not start, does it crank slower than normal, faster than normal, or at the same speed as normal.

2.  Has the check engine lamp been coming on?  If so, have the diagnostic trouble codes checked.  Your local parts retailer may be willing to read the trouble code for free.  I'd like to know the numerical code(s), if any, stored in the engine control module.  If you've already checked the trouble codes regardless of the check engine lamp coming on, please include them in your follow-up.

3.  When the problem occurs, check to see if you are getting spark.  To do this, prepare yourself by removing the cover over the spark plug wires and having a spare spark plug handy.  When the problem occurs, remove the #1 wire from the #1 spark plug.  Put the spare plug in the wire and lay it on the intake manifold.  Then, crank the engine and observe whether the plug sparks.