K75 not starting ( let out your inner Sherlock Holmes)

[Laitch]

At your first post you wrote that the values at the temp. sensor were correct, so you have now found the fault in the wiring to it. Good catch! Let us know how it runs.

 :clap:

[failedmechanicnico]

At your first post you wrote that the values at the temp. sensor were correct, so you have now found the fault in the wiring to it. Good catch! Let us know how it runs.

 :clap:

Since BMW uses these sensors, with different values on different bikes/cars I checked the resistance directly at the sensor after unpacking it, to make sure it was the right one.  :bang-head:

In hindsight I really should have done the tests before and after conecting it.

[The Mighty Gryphon]

Hope you stick around the forum.  The brain trust could use another knowledgeable rider like yourself.

[John Lang]

I still need Sherlock. I understand that water temp is a factor taken into account by the EFI but if you have spark and fuel, how does a non-functioning temp sensor prevent ignition?

[Martin]

Makes the mixture too rich for it to ignite. When you suspect this is occurring pull the fuel pump fuse, you should then be able to start the bike running on what remains in the combustion chamber. As the bike fires up replace the fuse and by manipulating the throttle you can keep it running. I've had it happens twice in 19 years, a bad connection was the cause.
Regards Martin.

[John Lang]

Thank you, Martin.

[Kai Ju]

That's interesting. I've spent most of my wrenching time on Japanese bikes so I'm used to the ECU defaulting to a 'warmed up' value if the ECT sensor fails while the engine is running. This allows the engine to continue to run, but would then create a lean condition on cold start and make the engine difficult to start.