Is this crank position sensor bracket original?

Jonohhh

True Classic
Something that has struck me as quite odd for a while is that my 85' FI car (which of course, has the Bosch Distributor based electronic ignition) has a tab mounted on the engine near the crank pulley for what clearly seems like a crankshaft position sensor. Based on the photos I've seen, it seems to be mounted where the timing tab is on most of the engines I've been able to see online.

I'm not entirely sure, but it looks a lot like the factory CPS bracket for the Uno Turbo with the Motronic FI...which is interesting because I can't seem to find a picture of a FI X1/9 with this unnecessary bracket.

That leads me to believe that potentially, something is or was going on here, although I don't really have enough clues to be able to draw a reasonable assumption.

in the same week I also found that the FI harness grommet at the firewall has most definitely been messed with, and is all sorts of pushed through and tangled up.

PXL_20220625_080458954.jpg


Ignore the coolant coming out of what seems to be one of the motor mount bolt holes. That's a thread for tomorrow 🫣
 
I always wondered that that hole was for. By the way, in your picture it looks like the tab with the timing pointers (o-5-10 degrees) has been cut off that bracket. Or is it just the angle of the picture?
 
I considered using that bracket to mount my crank ignition trigger sensor to. However it did not align well with everything else in my case. Perhaps if one could find the correct pulley with the included trigger ring that matches that mount - as well as V-groves that match the rest of the drive pulleys on the engine, plus a suitable sensor that will fit the hole, then it could be a useful mount.
 
I considered using that bracket to mount my crank ignition trigger sensor to. However it did not align well with everything else in my case. Perhaps if one could find the correct pulley with the included trigger ring that matches that mount - as well as V-groves that match the rest of the drive pulleys on the engine, plus a suitable sensor that will fit the hole, then it could be a useful mount.
Not wanting much are you?
 
If you study the crank pulley. there is a spot machined out of it that could potentially be used to let a trigger see 1 missing spot to a circumference. Never heard of that protocol. but just an observation. It is on the dohc anyway
 
I considered using that bracket to mount my crank ignition trigger sensor to. However it did not align well with everything else in my case. Perhaps if one could find the correct pulley with the included trigger ring that matches that mount - as well as V-groves that match the rest of the drive pulleys on the engine, plus a suitable sensor that will fit the hole, then it could be a useful mount.
I used it with a digital cam sensor and a 60-2 trigger wheel. The diameter of the mount was a little bit too big but it worked out very well. The digital cam sensor works up to 8500rpm on the crank which is good enough for my setup.
kamaxelsensor.jpg
 
If you study the crank pulley. there is a spot machined out of it that could potentially be used to let a trigger see 1 missing spot to a circumference. Never heard of that protocol. but just an observation. It is on the dohc anyway
Same on the X's pulley. I thought maybe it could be used as a secondary "TDC" reference with some aftermarket ECU's. Perhaps in lieu of a cam position sensor or such for example. But no idea why you'd need that.
 
I used it with a digital cam sensor and a 60-2 trigger wheel. The diameter of the mount was a little bit too big but it worked out very well. The digital cam sensor works up to 8500rpm on the crank which is good enough for my setup.View attachment 63086
What trigger wheel did you use? A add-on item or was there a stock Fiat pulley with the trigger wheel that worked?
 
I recall the FI Yugo had a front pulley with a built-in trigger wheel, and a front oil seal cover with a sensor mount (cast aluminum). Not sure if the stock Yugo sensor would work with a standalone ECU but the other two components would work on a X engine.
 
Awesome, thanks people, I now understand that it is correct - just that the timing tab has been cut off as Carl pointed out.

I can't say it doesn't make me start thinking about the "what ifs" every time I see that crank sensor bracket. But I should probably focus on the multitude of other projects going on at the moment. Hopefully my E36 that just overheated on the way to prep for an exam tonight hasn't volunteered me for another 😒.

I'm always suspicious about potential non OEM things i find on this car. Between the multitude of aesthetic mods, wheels, and the absolutely blown apart first gear on the original transmission, I'm always suspicious about what this cars past life entailed.
 
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I purchased the whole front pulley/sensor setup off an Uno Turbo block that was available purely as it was available then and unlikely in the future when I needed it.
If you look closely at the crank pulley there is a marker at 12 & 6 I assume the sensor is designed to pick up.
Thinking ahead my only problem is I have a/c so will most likely need to find the a/c equivalent which I’m not sure Uno Turbo ever had a/c so likely need to find equivalent setup off an equivalent single cam variant which has a/c, Punto, Brava, Bravo, Stillo 🤷‍♂️
49EC119E-7F69-43BD-854D-8FAA7E56467C.jpeg
 
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I purchased the whole front pulley/sensor setup off an Uno Turbo block that was available purely as it was available then and unlikely in the future when I needed it.
If you look closely at the crank pulley there is a marker at 12 & 6 I assume the sensor is designed to pick up.
Thinking ahead my only problem is I have a/c so will most likely need to find the a/c equivalent which I’m not sure Uno Turbo ever had a/c so likely need to find equivalent setup off an equivalent single cam variant which has a/c, Punto, Brava, Bravo, Stillo 🤷‍♂️
View attachment 63095
Do you have another image showing the teeth on the main pulley?

Thank you.
 
I purchased the whole front pulley/sensor setup off an Uno Turbo block that was available purely as it was available then and unlikely in the future when I needed it.
If you look closely at the crank pulley there is a marker at 12 & 6 I assume the sensor is designed to pick up.
Thinking ahead my only problem is I have a/c so will most likely need to find the a/c equivalent which I’m not sure Uno Turbo ever had a/c so likely need to find equivalent setup off an equivalent single cam variant which has a/c, Punto, Brava, Bravo, Stillo 🤷‍♂️
View attachment 63095

Hmm. Seeing that gives me an idea.

Trigger wheels don't *have* to be wide at all...there are many OEM applications with just a simple piece of sheet metal (NB Miata, Mitsubishi Evo).

With a bracket that places the sensor closer to the engine it sure seems like it'd be close enough that you could put a sheet metal trigger wheel behind the crank pulley so you don't have to go through the hassle of changing every pulley or bracket out with ones with different offsets. I guess the question is if the pulley can afford to be a millimeter or so misaligned?

Of course, that's unnecessary if the UT pulley does have the same offset but I'm not too sure to be honest.
 
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What trigger wheel did you use? A add-on item or was there a stock Fiat pulley with the trigger wheel that worked?
I machined the stock Fiat pulley on the lathe. I removed 5mm from the inside/10-12mm deep. Then machined an after market trigger wheel with a slightly bigger outside diameter than the pulley to fit with heat/press.
5mm in is as far you can go without touching/damaging the belt track on the pulley.
Note that the Fiat pulley is made of cast iron, and the lathe didn't like it much.
 
Do you have another image showing the teeth on the main pulley?

Thank you.
Would be more than happy to send you a close up but unfortunately those parts and many others are packed in a crate in the UK awaiting shipping to Australia☺️

I do have this pic of the parts and if you zoom in you can see the pickups are part of the cast pulley wheel.
28ACF888-4074-4EA6-B217-54583926BB50.jpeg
 
Would be more than happy to send you a close up but unfortunately those parts and many others are packed in a crate in the UK awaiting shipping to Australia☺️

I do have this pic of the parts and if you zoom in you can see the pickups are part of the cast pulley wheel.
View attachment 63104
Perfect thanks. So this is TDC sensor with a two teeth (correction from the initial post). The offset from the TDC mark on the pulley relates to the tooth relative to the sensor placement. In the original pic I now see there are two teeth across from each other (one can just see the little nubs).

Why the two teeth, showing my ignorance or inability to parse the why…

A bunch of different details on this engine the more one looks. (Hanger engine mount instead of snail for example)

Thank you very much.
 
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