No spark on Cyl 2 - MSD80 related?

Dramat1ca

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Jul 10, 2018
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n54 335i 6MT
I'm currently having issues getting my 335 back on the road and I was hoping I could get some feedback

Car is FBO / Motiv flex fuel / MHD tune by Wedge

TLDR version of the story is I blew out my mosfets, (30BB) sent them to a computer repair shop to get replaced, instead of replacing just the 6 he actually went and added an EXTRA mosfet on to the board. If you are familiar with what this DME looks like there is an open spot for a mosfet on the msd80 board. I don't know if this caused any issues before I noticed it and removed it. I tested all mosfets for continuity - no problems there.

the repair got rid of my 30BB code but afterwards I had injector codes (2E34 Fuel injector, cylinder 5, activation) and a misfire on cyl 2 (2E29 Firing Cylinder 2). I checked and found two injectors were in fact bad by testing them with my meter. Replaced all 6 with FCP remanned index 12's and coded them with inpa. I had to code them twice but I was able to get rid of that 2E34 code afterwards.

Now I'm trying to figure out this cyl 2 misfire, I checked a known working plug/coil combo for spark on cyl 2 and got nothing. I traced the orange power wire from the coil pack connector back to the ecm and found the wire was nicked. I fixed the power wire, confirmed the repair and tried to start the car. - no change. The signal wire is good as well so now I feel like I'm back at the DME again. I assumed if the DME was having issues I would get some sort of internal fault code.

Any Ideas? I'm just not convinced its my DME quite yet.

Thanks for any advice you guys can provide!
 
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Threetirtyfive

Corporal
Jan 9, 2019
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335i
The MOSFETS drive the injectors not the coils, to correct a lot of misinfo about this.

So it could still be a MOSFET issue regarding the code for the fuel injector. Incidentally sometimes cylinders are given in firing order and sometimes in cylinder order, so the cyl 2 issue is probably the same as cyl 5. If they added a MOSFET to the board perhaps they've cocked something else up, the gold tracks are easily broken. Can you open and photo their repair in HD so the MOSFET part numbers are visible?
 
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Dramat1ca

Lurker
Jul 10, 2018
10
3
0
Ride
n54 335i 6MT
I really appreciate the response!

I went to this website and found a great breakdown of MSD80 and decided it would make sense based on what I'm encountering to change it up. (its in 4 parts) Bimmer Profs MSD80

Just sent it off to get swapped to MSD81. I should have it back in a day or two to see if it is fixed. Next I need to find out if I have to re-purchase all of my MHD licenses since I'm going from I8AOS to LJEOS. ...And if I can still use my custom tune from wedge or if they need to send me a new file because of the switch.
 
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