C3i help needed.


Well-Known Member
Just replaced a complete harness on an '87 TR. Car was running fine before the work. After the install, car will not fire. Tracked it down to a no spark condition.

This is what we have found so far:

1.) There is 12 volts at the cam sensor.
2.) No voltage at crank sensor
3.) Cam sensor is acting a little funny; the reference is always around 3 volts in the full 360 degrees of rotation.
4.) Tried 2 other working coil pack/ignition modules
5.) Tried 3 known good cam sensor caps.
6.) We have 12 volts coming into the module in both spots (ecm and c3i fuse)
7.) grounds are ok.
8.) fuel pump is coming on when cranking the car.
9.) scan tool is not showing rpm
10.) checked out the harness plug for bad connection. We think we have eliminated that.

Is there always 12 volts at the crank sensor with the key on? Did not have another car around to check this. I was thinking that it may only get 12 volts after the car gets the cam sensor signal.....which would lead us back to the cam sensor issue mentioned above.

Thanks in advance!