I have a 1998 Accent MVi 1500, 16v, I parked it up and and wet back out to start after about an hour and it would not start, the next it started no problem,sometimes its ok other times itwont start, it turns over but wont fire up, I have been told that it is the crank sensor, can anyone tell me were it is located on the engine and how difficult it is to change. Cheers

 

Before you start changing parts you should check the computer for codes. If thecrank position sensoris bad, it should throw acode and light the check engine light. Are there any codes in the computer?

 

[sm=signs007.gif]I have put an OBDII on the car but it showed no codes although the car was running at this time and it is at the moment, even when it wont start it still dosnt show a code,it seems to be when it gets hot but not every time it decides not to run, the main dealer pointed towards the crank sensor but could not be certain,any info or ideas would be helpful as I dont trust the car at the minute.

 

The sensor wheel is at the back of the crankshaft so ethe sensor will be at the rear of the motor (bellhousing area).


DESCRIPTION[/align][/align]
When replacing the Crankshaft Position Sensor on a 1996 to 1999 Accent, Elantra or Tiburon, it is important to note differences in the construction of the original sensor and the replacement sensor.[/align]
[/align]The sensor construction was modified in 1997. The sensor's housing material was changed from a metallic design to a plastic design (as can be seen in the pictures below).[/align][/align]Comparison of crankshaft position Sensor Housing (39180-22050)[/align][/align][/align][/align][/align][/align]NOTE[/align][/align]
It is very important, when replacing an old style sensor with a new style sensor, that the O-Ring and the plastic washer be removed from the sensor mounting hole before the new sensor is installed.
If the O-Ring and/or the plastic washer is not removed from the sensor mounting hole, the new sensor will not fit properly.
[/align][/align][/align]
Crankshaft Position Sensor Mounting Hole with the O-Ring in Place[/align][/align][/align][/align][/align]
Crankshaft Position Sensor Mounting Hole with the O-Ring properly removed[/align][/align]--------------------[/align][/align]TROUBLESHOOTING HINTS
a. If the engine is hard to start when hot, check for fuel pressure and injector leaks.
b. If the injector does not operate when the engine is cranked, then check the following:
1) Faulty power supply circuit to the ECM and faulty ground circuit
2) Faulty MFI control relay
3) Faulty crankshaft position sensor and camshaft position sensor
c. If there is any cylinder whose idle state remains unchanged when the fuel injection of injectors is cut one after another during idling, check each cylinder for the following:
1) Injector and harness
2) Ignition plug and high tension cable
3) Compression pressure
d. If the injection system is OK but the injector drive time is out of specification, check for the following items.
1) Poor combustion in the cylinder. (faulty ignition plug, ignition coil, compression pressure and etc.)
e. The MIL is on or the DTC is displayed on the SCAN TOOL under the following condition.
1) When the injector itself is faulty. [/align][/align][/align][/align]--------------------[/align][/align]TROUBLESHOOTING HINTS[/align][/align]a. If the engine is hard to start when hot, check for fuel pressure and injector leaks.
b. If the injector does not operate when the engine is cranked, then check the following:
1) Faulty power supply circuit to the ECM and faulty ground circuit
2) Faulty MFI control relay
3) Faulty crankshaft position sensor and camshaft position sensor
c. If there is any cylinder whose idle state remains unchanged when the fuel injection of injectors is cut one after another during idling, check each cylinder for the following:
1) Injector and harness
2) Ignition plug and high tension cable
3) Compression pressure