Please help with this spark problem

[Cldamman]

Hello thank you for reading, ok so my dads friend gave me this k75s sweet right? He got it from someone that thought they were a bmw expert so you can guess from there lol, everything was apart so I reassembled accordingly and connected all the connectors and put gas and a battery in it and went to fire up and no spark, so I began to research.. A lot.... Couldn't find anything pertaining to my situation so i started hunting things down, ignition box: replaced, efi brain: replaced: wiring harness: replaced coils: replaced, luckily the man next door to our Harley shop has a ton of k100 parts and k75 parts, still nothing all lights come on except water temp light and it cranks over the fuel pump works just no spark, I turned my attention to the hall sensor, tested that maybe it might be bad, I get 12v to the coil but nothing is telling it to spark, for the hell of it I put a k100 hall sensor thinking that it won't spark at the right time but it will still spark but nothing, I literally don't know what to do now, should I change the boxes again? I have about 3 or 4 each lol but only one hall sensor and I don't want to spend 500 if I don't need to, please help me and thank you lol  :dunno2:

[TimTyler]

Have you seen this? http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/bike-wont-start1.htm

[Cldamman]

Yes I downloaded that and followed that as much as I could it's mainly for a k75 and the hall sensor diagram doesn't say which side it's from plug wise

Edit it's mainly for a k100 sorry

[rbm]

The EFI won't generate signals for the coils if the hall sensors doesn't send a signal to it during cranking.  It's a fair bet that the HES or the wiring to the connector is defective.  Time to check.  There's instructions for building an ignition/ABS tester available, but you could also use a simple 12V LED.  Instructions for testing and replacing HES are also available for the BMW Oilheads but it applies equally to the K-bikes.

Pinout for the K75 / K100 HES, viewed plug-wise:

[Cldamman]

See my 3 and 4 are opposite according to that diagram for the k75 my #4 is hot and #3 is ground

[Scott_]

See my 3 and 4 are opposite according to that diagram for the k75 my #4 is hot and #3 is ground

This is what my schematic shows:


#4 is hot and #3 is ground like you suggest.

[Cldamman]

Now correct me if I'm wrong but can't i plug in a hall sensor from a k100 and it won't spark on the right time but it should still spark right?

[Scott_]

Yes, I would think that it should cause spark, though like you say, at the wrong time.

[Cldamman]

So if I do that and no spark would that be the ignition module? And is there a way to test a module itself?

[Scott_]

One thing you could check is if you have +12v at terminal #10(green/yellow wire) and a good Ground at terminal #1(brown).
Check for +12 at each coil(green/yellow). (the coils are grounded in the controller)
The +12 for these is from fuse #1, fed through the kill switch from the ign switch.

If you were reading +12 at the hall sensor plug, you will most likely have it at the controller as the hall sensor gets it from the controller on #2

Didn't you say in your first post that you already tried a different ign controller?

[Cldamman]

I will check that in the morning I do know I Have power at the hall sensor and all the coils voltage wise I don't know and I'm assuming you want me to unplug the ign sensor before testing right? And I was wondering if I should replace the ignition sensor cause I don't know what else would be the problem lol

[Scott_]

If you are getting a reading at the hall sensor, then you should be good for power. No need to further check term #10. If you had no power there, you would not have it at the hall sensors.

If you have another ign module to test with, then I'd say yes, change it and see what happens. The one you have obviously isn't working properly.

If you have one in your assortment of parts, make sure that the part # matches. I don't think that a module off of a 100 will work on a 75.......

the BMW # for the 75s ignition control module is 12 14 1 459 021 (with jetronic fuel system)
an alternate BMW # for the ignition controller could be 13 61 1 464 238 (with L-jetronic fuel system as part of "anti-interference kit" for 'official' vehicles. AKA police bikes.....)
the BMW # for the 100 2v ignition controller is 12 14 1 459 018 (with jetronic fuel system)

Bear in mind that the BMW part# is most likely not the same as the controllers mfgr part #, and no guarantee that the BMW part # will even be on the controller housing.

[Cldamman]

When I went over to this mans shop I took every module that had the 3zyl mark on it, so I hope all the 3 cylinders are the same, this is why the bike confuses me so much lol they arnt suppose to break down. I normally work on Harley's and I will say these are completely different

[Cldamman]

All the ignition modules I have say it's for 12v-3zyl and the number is 0227401003

[Scott_]

Well the Bosch numbers are the same, so all you can do is try... can't be any worse than it already is.......

[Cldamman]

Ok so today I took the k100 hall sensor drilled the river out and stuck them on the k75 plate and it shocked the hell out of me lol, so I have spark just have to figure out how to secure them to the plate and hope that it isn't backwards, got it to fire on one cylinder I think might have clogged injectors idk

[K75RT Keith]

Do a internet search for R1100 HES or Hall sensor.  there is/was a piece on replacing the sensors on the plate.  Same sensors as the K uses

[bmw-rider]

Hi,
http://advwisdom.hogranch.com/Wisdom/oilhead_hall_sensors.pdf