Question2003 Hyundai Accent after driving and turn off after it's got warm will turn over but will not fire up until cools off what could be the problem. I just put in a new fuel pump and filter thought that was it but still happening.
AnswerHi, Dianna. I've seen this issue occur due to a defective crank sensor. Often they fail when hot and then work normally again once they've cooled off. This could also be caused by a coolant temperature sensor (or other engine management sensor) reading incorrectly. In all the cases I've mentioned, the check engine lamp being illuminated is typical.
Here's how I'd recommend approaching this:
1. Is your check engine lamp on or has it been coming on? If so, check for trouble codes. Chances are you'll have a code related to the specific cause of your problems.
2. When the engine won't start, make a not of whether the check engine lamp illuminates when you turn the ignition to the "on" position. If not, there's likely an issue preventing your engine control module (ECM) from powering on.
3. Check to see whether you have spark at the spark plugs. To do this, simply make use of an old spark plug (or purchase a new one if you desire). Remove the #1 wire from the #1 plug and install the old plug in the wire end and lay the plug on the intake manifold. While an assistant cranks the engine, observe to see whether you have spark at the plug. If not, suspect that the ECM is not seeing the information it needs to determine when to fire the coils (most notably, the crank sensor). If so, suspect an issue with the one of the sensors for the fuel injection system.
