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lost sync v3.57

Posted: Sat Dec 05, 2009 8:26 am
by spyro
i have a megasquirt v3.0 thats was working ok but i bought a new one v3.57 to replace the 3.0
vr sensor / 60-2
now im getting lost sync above 3000rpm i have tried to tune the pots , tried to reverse polarity but the problem stays the same
why does it work ok on the 3.0 and not on the 3.57 ?

Re: lost sync v3.37

Posted: Sat Dec 05, 2009 9:27 am
by jsmcortina
That is strange. Difficult to tell what is going on without an oscilloscope.

Have you used the "lost sync" composite logger to see what tooth pattern you are getting when it loses sync?

James

Re: lost sync v3.37

Posted: Sun Dec 06, 2009 3:08 am
by prof315
spyro wrote:i have a megasquirt v3.0 thats was working ok but i bought a new one v3.57 to replace the 3.0
vr sensor / 60-2
now im getting lost sync above 3000rpm i have tried to tune the pots , tried to reverse polarity but the problem stays the same
why does it work ok on the 3.0 and not on the 3.57 ?
I have had the same problem with MS2/Extra and a 60-2 tooth wheel. Matt Cramer hooked me up with a simple fix. Just add a 10K resistor to the signal line. I have done this on 5 MS2/extra installs that were using a 60-2 tooth trigger wheel and it fixed all of them. They were all 3.57 boards but I had the same problem with the one v3.0 board I have built. The 3.0 board install wound up with a 36-1 tooth wheel for other reasons.

Re: lost sync v3.37

Posted: Sun Dec 06, 2009 5:57 am
by spyro
im going to try that today

Re: lost sync v3.37

Posted: Sun Dec 06, 2009 6:54 am
by spyro
prof315 wrote:
spyro wrote:i have a megasquirt v3.0 thats was working ok but i bought a new one v3.57 to replace the 3.0
vr sensor / 60-2
now im getting lost sync above 3000rpm i have tried to tune the pots , tried to reverse polarity but the problem stays the same
why does it work ok on the 3.0 and not on the 3.57 ?
I have had the same problem with MS2/Extra and a 60-2 tooth wheel. Matt Cramer hooked me up with a simple fix. Just add a 10K resistor to the signal line. I have done this on 5 MS2/extra installs that were using a 60-2 tooth trigger wheel and it fixed all of them. They were all 3.57 boards but I had the same problem with the one v3.0 board I have built. The 3.0 board install wound up with a 36-1 tooth wheel for other reasons.

thanks i didnt had a 10k resistor, only a 15k but it solved the problem , now it revs clean to 8000, i have to test it on the road, but it seems ok

Re: lost sync v3.57

Posted: Sun Jan 09, 2011 8:16 am
by fred d.
hi all ,I have the same probleme whit a 3.57 ms2
36-1 optical
I have 2set up exactly the same one it a v.3 and its fine and the 3.57 lost sync around 6000 and 6400 rpm
the reason is always 2
now i just try to add the 10K resistor and still exactly the same probleme same rpm and same code
what is the next step to check ?

Re: lost sync v3.57

Posted: Wed Jan 12, 2011 10:29 am
by Matt Cramer
fred d. wrote:hi all ,I have the same probleme whit a 3.57 ms2
36-1 optical
I have 2set up exactly the same one it a v.3 and its fine and the 3.57 lost sync around 6000 and 6400 rpm
the reason is always 2
now i just try to add the 10K resistor and still exactly the same probleme same rpm and same code
what is the next step to check ?
Could you please post a tooth log of it losing sync? That will shed more light on the situation.