Crankshaft position sensor

It could cause loss of spark if the sensor is not reading properly it must be all the way in

How sure r u of this that starter was a bitch I really don't want to pull it again..it popped like it seated when I put it in

Look at it with a mirror if u have to to see its in properly. And yes this will cause it not to start

Or the harness is worn, or a bad connector, The CKP sensor should be sending an AC voltage square wave signal when engine is cranking. Check it with a multimeter IF, you have one... Inspect the harness before pulling the sensor again.