MoTeC Global Forum

Hi All
this my Gen 1 busa capture
your advice would be greatly appreciated
I have " played " with voltages and filtering but still do not have sync
I am sure there are others with Motec on their busa so it may be of help to others
thanks in advance
harky

Further to my post
The crank is 24-1 and the missing tooth and the sync " pin" align @ the same time ! Which is not in the Motec rule book
Others must be using this enigine as is !
The early 99 model had a 8 missing segment flywheel , and that changed to the 24 in about 2002
I am using a 2004 engine
Looking forward to any advice
Cheers
Harky

Hello Harky

Try ref/sync mode 69, it is designed to work with this type of signal arrangement.

The help in ECU Manager gives more information:

69 : One missing tooth twice per cycle Gap based Sync
Requires active Sync edge to land within missing tooth window and
remain there. Not suitable for active camshaft engines.

Thanks for the reply Alan
Mode 69 looks the go B. B. But
It is for a gap based sync
The hayabusa has a " pin" for the sync signal
I read all the other Oem. S thinking something else night do the Job
These engines are a universal power plant so I am thinking there is a solution
Hoping for any other advice
Cheers
Harky

Hello Harky

I'm not sure what you mean by "looks the go B. B.", can you elaborate?

But anyway, mode 69 is correct. When it says it is gap based sync it means that it is looking for the sync signal in the crank missing teeth gap, which is exactly what your ref/sync capture shows.

Thanks for your quick reply Alan
I still don't get sync with 69
I will look at it further

The go. Is Ozi. Talk for " that will work ".
And b. B Is me saying. But. But

So back to my workshop
Thanks for you help
Cheers
Harky

Thanks for the Ozi update, makes sense now!

To further investigate, try taking the spark plugs out then crank the engine and see if it syncs. The reason is that your ref/sync capture shows some pretty big cranking speed variation, and this can make it difficult for the ECU to spot the missing teeth.

If it does sync then put the plugs back in and try increasing the Tooth Ratio parameter in steps of 10%. You may also need to look at battery size and wire gauge from the battery to the starter motor.

While cranking with the plugs back in, go to the diagnostic errors screen (press D), press 'Reset Errors' and make a note of which ones come back.

I m back
I have done all the suggestions
without the plugs
still i have no sync
often no faults , and no sync
this capture is with a boost battery , I am see a crank speed of 700+
Q is the percentage number still relevant with mode 69 because it says only relevant to modes 2-4 or something like that ? I have shifted to 70% in small incoments
one thought I had is to cut another tooth off the crank wheel !
seems a bit drastic
I have set the correction voltage s and time correction to different levels
the sensors have falling signals !
so here is the latest capture
it sure is a useful tool , I had alot of fun with an M4 trying to get the same picture

The sync signal in that capture is not good, specifically the spike in the sync signal that occurs 16 crank teeth before the actual sync signal. You really need to fix this as it will cause problems.

You say "often no faults", implying that there were sometimes faults. Could you give details of what those faults were?

Also, what filter and mag levels are you using? Maybe attach your ECU file.

Thanks Alan for you help
The sync sensor is a 5mm pin that sits 5/6 mm out of the cam , so visually there is no mechanical interference
The loom is a Motec unterminated loom so shielded for the ref and sync , both are "earthed " at the sensor with the 0 v loom wire , being a bike the length is very short. Eg the sync wire is about 350 / 400 mm long
I will separate the sync loom from the main loom , is external shielding of any use ?
Is there any other spike source I should be looking for ?
Once again your input is greatly appreciated
Cheers
Harky