Hyundai Repair: puzzling, coolant temperature sensor, crank sensor


Question
I have a '98 Hyundai Accent sport model that has a puzzling problem. You can drive the vehicle a short distance and after it has stopped will refuse to start agian for about 5 hours or so. You can hear the car turning over but it just wont start. Also, one time I was driving it and stoped at a stop light it shut off on its own. Very quietly I might add as if I had turned off the car myself. We have talked to some mechanics and they thought it may be the ignition module, we replaced it but has not fixed the problem. Please help!

Answer
It sounds like you may have an issue with your crank sensor or coolant temperature sensor.  If your check engine lamp is coming on, start with reading the diagnostic trouble codes.  

If you've got no trouble codes, the key to finding the problem is to have a good driveability technician inspect the vehicle while the condition is occurring.  But there are some pieces of information you can give that may assist in knowing what the possibilities are.  Right now, there are many.

Does the check engine lamp come on for at least a few seconds when you turn the ignition key to the "on" position?
Do you have spark at the spark plugs?
Do you have appropriate fuel pressure?

Your car doesn't have what's typically called an ignition module.  All ignition functions are controlled by the main Engine Control Module (ECM).  When you say the ignition module was replaced, are you referring to the ECM or something else?