Need a Crankshaft Position Sensor

[Sechserreihe]

Hi all,

I'm needing a crankshaft position sensor for my 1985 B6 2.8. A regular old CPS from a BMW M30 engine will not work. Something about it being binary. If anybody could spare one that would be great.

Many thanks in advance.

Mark Columbus Ohio USA

[Sechserreihe]

I've talked to the repair shop that had the car (years ago) to try and solve this non-running issue. They have informed me that the Flywheel sensor (CPS) on these cars is a special Alpina unit that is binary. It was designed to speak to the Alpina smart box due to the modifictions they had made to the fuel metering, camshaft, compression ratio, etc. A Bosch CPS would not work and would lead to issues I'm experiencing. The also mentioned that the smart box had been sent to Alpina-USA to be checked for faulty solder joints, etc but had a clean bill of health. The repair shop told me they weren't 100% sure if the correct Alpina sensor needed to be binary or vice versa. They remember Alpina stating the binary part was what makes them incompatible.

Alpina USA no longer carries this sensor. So I'm hoping with the help of the Internets, I can track one down or perhaps have one made??

Any ideas?

Thanks,

Mark

[Charles]

If you haven't already done so, I would recommend that for such a specialist item, you would do well to speak to ALPINA directly - they do tend to hold such curiosities in stock

[Sechserreihe]

Hi,
Yes, I've contacted Alpina and they've told me they're No Longer Available. The part number is 12 10 039.

Any help is appreciated.

Thanks,'

Mark

[jolls]

Hi,
Yes, I've contacted Alpina and they've told me they're No Longer Available. The part number is 12 10 039.

Any help is appreciated.

Thanks,'

Mark

Would that be Alpina Headquarters in Germany?

[Sechserreihe]

Yes, I've reached out to Alpina-USA and Alpina in Buchloe, Germany. Both said part is NLA.

[Charles]

Another route might be to contact the original sensor manufacturer to see if they have any smart ideas.

If ALPINA.de are saying it is NLA, then you might want to ask them for specification details to allow you to explore ways of getting a new one made up elsewhere?

I know I am scraping the bottom of the barrel with these suggestions, but I fear that you might be in for a long wait unless you are extremely lucky - in which case, perhaps you might choose my lottery numbers for me!!!

[simon13]

This will just use the stock BMW crank sensor from the standard BMW engine management of the time. So jetronic of some sort?

I think your repair shop and bmw have spun you a load of old cobblers! On this old stuff if the CPS isn't working then the engine gets no spark hence no start. The binary chat bollocks i'd say

If it won't start you need to go to basics. Timing correct? Fuel? Spark? go from there. Bar the old turbo B7 cars the engine managment on the NA engined cars just use the BMW technology of the time re tuned to their requirements

[Sechserreihe]

Hi,
I've already reached out to Alpina to ask them about the manufacturer of the sensor. I've not received a reply.

As far as just using a BMW sensor, I don't think that'll work because as someone over on the MyE28.com forum pointed out, my engine is combination of both J-tronic and Motronic!

''The Bosch ECU belongs to the M30B28 and B25 engines with L-JET. Those engines had an old school distributor with weights and vacuum advance.
BUT
Your engine has a motronic distributor. It looks like Alpina used that black box interface to make it all work''.

Please let me know your thoughts.

Thanks,

Mark

[Sechserreihe]

Here are some pix.

https://imgur.com/a/Plh178J

https://imgur.com/a/v2c7YcH

https://imgur.com/a/IqyMdrP

[Sechserreihe]

Here is a short video of what's going on. The car will not start (no spark - flash of timing light) when I first turn it over. Then, on the second try, it will start and run like crap. After a few seconds the timing light will stop flashing and the engine will die.

https://youtu.be/a2rXkvJFenA

[Sechserreihe]

Alpina was kind enough to share with me the who produced the CPS for them back in the day. It was AFT Atlas Fahrzeugtechnik. The company has since been bought a couple of times but is still around und the name Schaeffler Engineering. I shot them an email. Under the History link on their website, they have a smartbox for a distributorless ignition pictured! It looks similar to mine...

https://www.schaeffler-engineering.com/ ... s/history/

[E24man]

.

[Sechserreihe]

Oy Vey. Say it ain't so. I'm going to keep looking and hoping. What would it take to convert back? If it's just swaping out the distributorless igniton for a Motronic unit, that wouldn't be all too terrible.

Perhaps you could put me in contact with someone who has done the converstion.

Thanks,

Mark

[Sechserreihe]

Alpina sent me a parts catalog. Here are some pix of the sensor in question.

https://imgur.com/a/EnjyNkN