On the CPS, take a good close look at the blue wire (harness side); trace for any breaks, brittle areas, etc across the top of the motor. Also look at the wire it connects to on the CPS (it's red on mine)...same thing, trace into the CPS.
This is the NE signal wire...it provides engine rpm info from the 24 tooth gear inside the CPS to the igniter. The igniter in turn provides the rpm signal to the tach. If the ECU does not get this info, the car will not start (as you discovered) and it can cause an erratic tach reading.
This is the NE signal wire...it provides engine rpm info from the 24 tooth gear inside the CPS to the igniter. The igniter in turn provides the rpm signal to the tach. If the ECU does not get this info, the car will not start (as you discovered) and it can cause an erratic tach reading.