My son's 2000 neon's waterpump seized up and and it jummped time a nd ruined the engine.
I got a engine from the bone yard put on a new waterpump and timing belt. Installed the motor. The car started and ran fine for about an hour drove it around the block no problems. The car was ideling and stalled out and would not start. I pulled a plug put in the wire, Intermittant spark than no spark.
Any ideas what is wrong?

 

Sounds like a crank sensor.

 

I switched crank sensor with other motor, It didn't start. Than I switched cam sensors, car started and ran for about 10 seconds.
I bought a new crank sensor and a new cam sensor installed them and it wont start.
My nerves are getting shot with this problem.
Any ideas on getting this to start?

 

What year was the Neon you got the engine out of?
EDIT: Nevermind. You switched the sensor.

 

It was a loose wiring harness connection. I zip tied them together. Fixed !!!