Author Topic: No spark on stock BMW M20B25  (Read 8413 times)

Offline DMS

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No spark on stock BMW M20B25
« on: February 27, 2011, 01:00:34 pm »
Me and VEMS don't seem to get along. It's been years since I've run VEMS on my car and it ran back in the days (firmware: 1.0.37) I got the car from storage recently and I've updated to 1.1.86. Dumped the old config file and started a new one.

Engine info: Completely stock M20B25 (stock everything!)

Primary settings:


Ignition settings:


I checked:

1) power to the coil. (it's there)
2) the negative wire between vems and the coil is fine. (no resistance)
3) I checked the coil on my other E30 (works)
4) Cranking RPM is at 230 rpm and shows a stable value when cranking for longer amounts of time.
5) Vbatt stays above 12V during cranking.
6) The plugs are as good as new.

I've tried:

7) changed ign output from I259-1 to I259-3 and changed the coil negative wire from pin EC36-35 to pin EC36-36.
8) Increasing coil charge time to 3 ms

A few days ago with some other settings I did have spark. But I the order was wrong etc. The settings bove is how they are now.

Does anybody see something strange?

Offline mattias

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Re: No spark on stock BMW M20B25
« Reply #1 on: February 27, 2011, 04:04:39 pm »
You should use 1.1.88, .86 was never recommended. See http://www.vems.hu/wiki/index.php?page=GenBoard%2FUnderDevelopment%2FFirmwareChanges

Use my config (see signature) for good defaults for your engine.

Publish your own .vemscfg or .vemslog to get proper feedback on your problem.

What VemsTune version are you using?
Try 2011-02-24 which was just released. http://www.vems.hu/download/VemsTune/

Offline DMS

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Re: No spark on stock BMW M20B25
« Reply #2 on: February 27, 2011, 04:27:39 pm »
You should use 1.1.88, .86 was never recommended. See http://www.vems.hu/wiki/index.php?page=GenBoard%2FUnderDevelopment%2FFirmwareChanges

Use my config (see signature) for good defaults for your engine.

Try 2011-02-24 which was just released. http://www.vems.hu/download/VemsTune/

I used your config for a base setup.
I use 1.1.88 firmware (86 was a typo) and 2011-01.08 vems tune

vemscfg: http://www.vems.hu/wiki/index.php?page=MembersPage%2FJanSaenen%2FConfig
« Last Edit: February 27, 2011, 04:36:32 pm by DMS »

Offline mattias

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Re: No spark on stock BMW M20B25
« Reply #3 on: February 27, 2011, 10:10:28 pm »
 Please use the file upload feature to upload your config file so that you can provide a link to the raw file (zip file is nice):
http://www.vems.hu/filethingie.php (vems/vems)

Always use the latest VemsTune release, the most recent firmwares might depend on it to work better. 2011-02-24 was just released. http://www.vems.hu/download/VemsTune/
« Last Edit: February 27, 2011, 10:14:53 pm by mattias »

Offline DMS

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Re: No spark on stock BMW M20B25
« Reply #4 on: February 28, 2011, 08:37:30 pm »
I'm at school atm but it seems the mismatch of 1.1.88 and vemstune 2011-02-24 is most likely the problem since the ign outputs were all wrongly selected when I opened my vemscfg. I'll have a fluke scope from work to check the ignition outputs tomorrow just in case it doesn't work just yet.

On a side note: the new vemstune looks badass!! injection timing etc. You guys have come a long way!! DAMN!

Offline DMS

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Re: No spark on stock BMW M20B25
« Reply #5 on: March 01, 2011, 06:45:47 pm »
OK confirmed: it was the mismatch of 1.1.88 and vemstune 2011-02-24.