Hyundai Repair: 1997elantra hard to start after changing cranksensor, crank sensor, new sensor

Question
i have a 1997 elantra with the 1.8 engine. check the codes in pcm it said the cranksensor was bad so i changed it and the car would notstart. i unhooked the battery and hooked it back up and still the car would crank but not start... i read in the hayns manual it saind to check the fuel pump and would not come on with the key but if i use the pump check connector and it came on and the car would start after cranking on it for about 20 sec, after it starts it runs gteat if u shut it offafter it gets hot or drive it for 20min and shut it off it will not untill it cools off.. but its the same thing all over again.  if u could help that would great thanx for your time

Answer
I see this alot, When you replaced the crank sensor the O Ring seal on the old crank sensor stayed ine the block. (Most likley anyway) If you still have the old sensor lying around check to see if the ring is on the sensor. It is similar to a rubber band. If not it stayed in the block and is causing the new sensor to be too far from the trigger wheel and not run. To repair it you will need to remove the sensor and get the old seal out. Make sure you have only one seal on the sensor. Re insatll it and you should be good to go.
Hope this helps
Good luck