2 Crank sensors?? (pic)

[02 330xi 10 128]

Hey guys, haven't been around much lately have been working like crazy, sport bikes etc. Well back into the Bimmer family, E39 is running great, however just ran into an issue with the E23. 1985 735i, lost power going down the road at about 60, started 3 more times and now no spark. I verified it's getting fuel and has pressure. I believe it's the crankshaft position sensor, so I ordered it. Then I went underneath the car to take out the old one, and I see 2? So I went to realoem to check it out, and it comes up with a name as pulse generator for what I've always known to be the crankshaft position sensor (CPS). So my first guess is the junkyard one is going to be bad, do I need to replace these in pairs then? Any advice appreciated.

[MarcoZandrini]

There could be 2 sensors as other engines of the era have 2 sensors:
- top dead center (TDC) (pin)
- position sensor (flywheel teeth)

I had a 1985 325e that had 2 sensors. The TDC pin popped out and the car wouldn't start. Your picture shows that the 2 sensors are offset. I bet set up is the same as my old 325e.

I'd verify that that TDC pin is in place first. Pull both sensors and rotate the crank. If the pin is gone the car won't start. I bet, though, that the pin is still there and the position sensor is bad. Check their resistance with a digital volt/ohm meter and report back. Also, check the wiring adjacent to the sensors. Those connectors can deteriorate over time.