I am having trouble diagnosing the cause of my sync loss during cranking. It seems like I got good steady cranking RPM and consistent spark before I took this engine out for a rebuild, but it is back together and I have no spark. Not sure where I went wrong.
MS3 v3.57 w/ MS3X logic outputs to a Quadspark module which drives my EDIS-6 coils for wasted spark (i.e. no EDIS module)
Factory BMW 60-2 wheel & sensor w/ 10k resistor in line
I tried a few tooth 1 angles but I don't know what I'm looking at well enough to know whether that's my problem. MSQ, composite, and tooth logs attached.
BMW M20 Cranking Sync Loss
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BMW M20 Cranking Sync Loss
Tuning in Houston, TX area
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Re: BMW M20 Cranking Sync Loss
I'm seeing some noise pulses; try adjusting the VR trim pots for less sensitivity.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
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Re: BMW M20 Cranking Sync Loss
So if I am understanding and reading correctly, R56 on the v3.57 board should go clockwise as a start. I'll post back in a few minutes with results.Matt Cramer wrote:I'm seeing some noise pulses; try adjusting the VR trim pots for less sensitivity.
Tuning in Houston, TX area
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Re: BMW M20 Cranking Sync Loss
R56 went clockwise 1 turn and RPM is much better, pulses that shouldn't have been there went away. thank you.
Still no spark- any ideas on that? +12V to Quadspark and coils are good, grounds are good.
Without a scope, how do I test:
-0-5V logic output from MS3X to QS module (I tried a test light but couldn't see any dim flashes while cranking I would expect)
-High current signal from QS to coils
?
Still no spark- any ideas on that? +12V to Quadspark and coils are good, grounds are good.
Without a scope, how do I test:
-0-5V logic output from MS3X to QS module (I tried a test light but couldn't see any dim flashes while cranking I would expect)
-High current signal from QS to coils
?
Tuning in Houston, TX area
https://www.racebushings.com
https://www.racebushings.com
Re: BMW M20 Cranking Sync Loss
do the coils fire when using test mode?
1990 bmw 320i daily driver with m20b25 ms3 sequential fuel, 380cc injectors, d585 coil near plug, home made cam sync, launch control, fan control, vss, homebrew egt logging what's next????
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- Helpful MS/Extra'er
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Re: BMW M20 Cranking Sync Loss
Turns out the dwell was set too low. I started around 2ms (nothing) and ended up around 5.5ms cranking dwell. Thanks to all for the assistance!
Tuning in Houston, TX area
https://www.racebushings.com
https://www.racebushings.com