Harmonic balancer was replaced and ran for ten min then died I'm getting fuel but think timing got off is that a possibility?

Would the key being gone make it not start

you didnt say which engine.

well if the crank angle sensor is tied to the balancer position...yes would not be seeing the correct crank position and stop it cold turkey...did someone simply forget to put that little tiny stick of butter in there? Were there parts left over from the job?

4 cyl 2.3

I believe these do have a key on the crankshaft. I know some engines dont and if you remove the bolt the pulley can rotate seperate from the shaft. But in this case as the sensor would need to be looked at. what makes you think its not in time?

I have spark and fuel just thought that timing might be a good place to start

it would take destructive forces to sheer that key...just to let you know, someone forgot to put it in or the motor was dead-headed~

did you rotate it to TDC and it was not TDC?

Rotated the shaft a little when going back together and I put the key in myself I know it was in there to begin with