Sensor on vibration dampener

[tractorman]

I just changed the "front" crank seal on my '94 Corsica. All went well, but I have a question about a sensor. There's a sensor that reads off a ring on the vibration dampener. Now, I know this isn't the same crank sensor that runs the ignition... and this car doesn't have a tach. So what's it for?

[CNCguy]

I just changed the "front" crank seal on my '94 Corsica. All went well, but I have a question about a sensor. There's a sensor that reads off a ring on the vibration dampener. Now, I know this isn't the same crank sensor that runs the ignition... and this car doesn't have a tach. So what's it for?

That should be the 24X crank sensor for SFI. Your engine also has the 7X sensor in the rear of the block.

[bszopi]

It is the 24x trigger, but its not for SFI. That is done by the cam position sensor. The 24x trigger is used for finer resolution of the crank position at low RPMs (below ~2k IIRC). This allows for smoother idle and low RPM control.

[tractorman]

I see. Thanks.