Reference Sensors
 

Hello Everyone,
I know of the two reference Sensors on the 944 engine (one for measuring engine speed and the other for measurinfg crank position). I see those sensors listed second in this page from The Parts Bin website but what is this first sensor listed? Any ideas?

Thanks, Michael

http://catalog.thepartsbin.com/?year=1987&make=PO&imageField.x=20&imageField.y=12

They should be identical.

What they have listed there is something diferent though. Must be an efor in their catalog, eh?

I think the double overhead cam model uses just the one sensor for both speed and tdc measurement and has a different connection because of this. If you have two sensors you need the lower of the two in the catalogue.

The two reference sensors are identical, same part#
But there is also a TDC sensor located next to the reference sensors.

Really? I haven't come across that third sensor . I'll have a peek this weekend. Thanks for the info folks.

Michael.

When you look at the engine from above, the TDC sensor is located to the right of the reference sensors on the same bracket.
It's round with a wire on it.

only later model 944 (85.5 and up I belive)have the third sensor it's just for diagnostics so you only need the two and they have the same part #
I had the three sensor model on the 87 engine I bought and I was told that the third sensor was totally unnesseary.

Actually I ran into this on my Early '85 944 which I think has the same motor layotu as the '87 924S. I had only the two identical sensors. I removed and replaced one for a broken connector, and removed and cleaned the other. They are magnetic so they pick-up bits of metal which may disturb the signal. Later motors have a seperate TDC sensor that is different and is mounted near the two twins.