What is the sensor in the front of the engine

[circlemblue]

What is the sensor in the front of the engine on a 1986 CSI? The one I am talking about connects on the top of the front and goes down next to radiator hose to connect to the bottom front of the engine. Is this what is refered to as a "reference sensor"?


Circlemblue

[CW6er]

It is the " Top Dead Center" sensor. In cars up to mid '87 it is only connected to the diagnostic plug. It has nothing to do with the running of the engine and is only used by test equipment. In the later cars, the sensors on the bellhousing were dropped and this TOC sensor, along with a pickup coil in the No. 1 spark plug wire are used for the ECU references.

[Golump]

Hello,

I suspect that my reference pin on the flywheel is gone. Can I wire this sensor at the front to the one which sits in the bellhousing to check if the car would start?

[alpinacsi]

Not very likely that the pin on the flywheel is missing. That seems to be more of an issue with the m20 and I have never experienced that with the m30. You should be a onto pull the inspection cover to see if that is the issue. How are the connectors for the speed and reference sensors on the top side? Should be on the intake to head brace at the top rear of the engine.

To answer your question: no you can not use the front sensor for testing.