Hyundai Repair: car not starting, coolant temperature sensor, hyundia accent

Question
I have a 2002 Hyundia accent gl with a 1.6 litre engine.It wont start when the temperature gets below 18 degrees. It turns over but it won't fire it acts like it is not getting fuel. As soon as it warms up it will start.I had the coolant temp sensor replaced and it does the same thing.What could cause this problem?

Answer
The coolant temperature sensor is the most frequent culprit for this condition, but there are numerous possibilities.  Since you've already replaced the sensor, it's probably safe to assume it's not the sensor in this case.

Here are the potential issues that come to mind:

-- Insufficient battery voltage.  It's possible the battery has enough power to crank the engine but not enough to keep system voltage sufficiently high during cranking.

-- Poor fuel.  The fuel is much harder to burn at cold temperatures, meaning that poor fuel quality may make the car hard or impossible to start.

-- Faulty crank sensor.

-- Faulty ignition coil.

-- Poor connection or short in any circuit critical for the engine control module (ECM) to operate the fuel management system.


Key tp solving the problem is investigating it while the symptoms are occurring.  Check your battery voltage during cranking.  It should be 10V or higher.  Check to see whether you have spark.  If you have the appropriate tools, check to see whether you have proper fuel pressure and whether the injectors are firing.