It could be bad with out turning the light on.
Faulty sensor get it replaced if not check to make sure wire isn't shorting out
Check to see if the wiring is damaged.
The crankshaft sensor in your 1990 former Roche is located on the front of the engine. The best way to test your crankshaft sensor is to hook the engine to a Dyno tester.
check the front of the engine at the bottom for an electrical plug
the crank sensor is on the passenger side of the car on the back of the engine. Check right up there by the transmission housing.
Check the crankshaft sensor. If the sensor on the Grand Voyager is bad then there wont be any spark.
Check the crankshaft sensor. Also check the timing and timing belt. The backfiring indicates that the engine is firing at the wrong time.
Check the crankshaft sensor. The sensor connector could be loose or the sensor could be bad. Try to read the engine codes to see if the computer shows an issue.
check the crankshaft sensor or the cam sensor.
check crankshaft sensor sensor
The crankshaft SENSOR shouldn't be much trouble. It's location depends on the manufacturer and the engine type. Check in one of the manuals that cover your car, like Haynes or Chilton and it shoud give you reasonably accurate information on the location of the crankshaft sensor. If you need to replace the crankshaft, first, remove the engine... Yes, it can be a pain but the biggest piece of machinery you will need is an engine lift.
You may want to check your catilick converter or your crankshaft positioning sensor.