We just finished installed complete engine and transmission back into the car after having the block built by ballistic motorsports. Running AEM EMS and when the key is on engine off the tach intermittently starts bouncing between 3 and 4 thousand rpm. When you disconnect the driver side cam position sensor it goes away. So we swapped out that sensor for a known good one off another S, same thing happens?????? We've checked the connections... could a crimped wire do this? Any ideas would be welcome.

 

sounds like grounding issues, try looking to see if the ground that goes on the back of the head is there... check the other grounds as well!

 

IT WAS... thank you. I never knew that bracket was also a ground behind the engine.