Which engine do you have?
The first thing to do is find a mechanic with a Chrysler DRB3 scanner. It will display "No" or "Present" for both signals while on a test drive. That will let you see which signal is dropping out.
Did your new crank sensor come with a thick paper spacer on the end? That is needed to set the critical air gap. If the gap is too large, the signal will be lost intermittently.
Besides the sensors, there could be a corroded splice between the two ground wires or between the two 8 volt feed wires. Also look for stretched terminal pins in the connectors.
Thursday, August 25th, 2011 AT 4:41 AM