Replaced the harmonic balacer & crank sensor but it will notcrank

What make vehicle ? model an year too. Some vehicles have two crankshaft position sensors .

24X and 7X Crankshaft Position Sensors/Harmonic Balancer Interrupter Ring

One sensor is in the side of engine block an the other is behind harmonic balancer

what year is it ?

1.9L the camshaft gear has an arrow bumped up from it's center. This arrow lines up with a dot on the cylander head. A mirror placed in front of the camshaft gear may help see the arrow and dot. The crankshaft mark is a bump up on the washer between the hamonic balancer and the timming belt gear. This bump is lined up with the middle slot of the indicator located right above the crankshaft and between the timingbelt. this mark is tough to see with the harmonic balacer still installed but can be seen with a little mirror. Another way to find TDC for the crank is on the harmonic balacer there is a sensor ring it looks like a gear with a tooth missing. T he sensor ring should be 9 teeth to the left from the space from missing tooth. If one way doesn't line up and the other way does then you need a harmonic balancer.

you will need a puller to take off the harmonic balancer, then you will see it. it has to line up perfectly with the balancer.

The crankshaft position sensor should be located behind the vibration damper/harmonic balancer and it will have to be removed before the crankshaft position sensor can be replaced. (Let me know if you require assistance with the proceedure)

Also, it usually requires a special tool to align that sensor (available from most auto part stores) and if the sensor is not properly aligned then damage to the sensor or the tone ring can occur.

Here is an image of the crankshaft position sensor with the vibration damper/harmonic balancer removed.

When my 94 Regal GS frequently wouldn't start for 30 minutes to an hour after being driven, it was the crankshaft positioning sensor that needed to be replaced. I also replaced the harmonic balance pulley. The car ran more smoothly and started everytime.

check harmonic balancer

Hello, the crank position sensor or (CPS) censor is located directly behind the harmonic balancer (or fly wheel at the very bottom). The sensor is located on the right side of the harmonic balancer when facing the front of the motor. You must remove the harmonic balancer to replace the sensor. You must also re-align the sensor with 30 thousands of an inch tolorence, or your car may idle rough or may not start. I own a 1990 Buick Century and just replaced my CPS sensor last month. There is a trick I learned to reinstalling the new sensor. Let me know if you need that information.

sounds like the same thing that was wrong with the 94 GS i recently bought. found the crankshaft postion sensor to be bad. it controls your electronic spark timing which would allow it to turn over with out starting.
also does your stall when you are stopped and at idle or while at driving speed or both? mine would stall at idle and driving speeds. Changed that sensor and have not had any more issues with stalling. sensor should cost around $30-$40 dollars at your local autozone, takes about 2 hours to change just need to pull the harmonic balancer pulley (make sure to use the proper tool or you will bend the pulley) and the sensor is behind the pulley. you will gain easier access to doing the maintenace buy removing the passenger front tire and the little splash gaurd directly behind the tire held on by 3 quick release fasteners. hope this helps you out.

The crank sensor is behind the harmonic balancer. Not too hard to replace, the harmonic balancer is supposed to come right off but I needed a big 2-jaw puller to get it off.... accessed through the wheel well.