MegaSquirt Flyback Modification

All questions about MS2/Microsquirt/Microsquirt module. See also MS2/Extra manuals

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Sprig
MS/Extra Newbie
Posts: 5
Joined: Tue Jun 26, 2007 8:11 am

MegaSquirt Flyback Modification

Post by Sprig »

MS FLYBACK noise causing problems has been a long known issue.

http://www.msefi.com/viewtopic.php?t=25984
"MS Voltage spikes"

http://www.msefi.com/viewtopic.php?t=27153
"wacky voltage spikes/lean on accel"

http://www.msefi.com/viewtopic.php?t=27258
"...some serious mis-fires or something else that is causing a very noticable stumble."

These are NOW dead links. They WERE active, and there were MANY MANY MANY More like them.

I can no longer host the main web page; I moved!

I can host the images, and insert the text comments of the page.

Does your Squirted engine exhibit any of these symptoms? (The ABOVE symtoms?)

This flyback modification should resolve these issues.

Cut trace above R3.

This removes the flyback voltage from the Battery Voltage sensor input on AD4-1.

Image

Cut trace to DB37 pin28 as shown here.

This isolates the flyback voltage from the main 12V input to the enitre board.

Image

Jumper S12 to the top of R3.

This is the new source of 12V for the Battery Voltage sense.

Image

Alternately, this source can also come from the non-banded end of D3.

Image

Jumper SPR4 to the top of the trace near DB37 pin28.

Image

This jumper can be routed under the MAP sensor.

Alternatively, the jumper can be attached from the top of trace to pin 6 directly.

Image LOST.

Install a 0.001uf capacitor into the bootloader header.

If C12 is provided with the kit, and isn't used in the stock location, it can be used here.

Image LOST.

IMPORTANT!!!

IMPORTANT!!!

Run a 18-16g wire from the connector DB37 pin6, through a 5A fuse, to the same physical connection that the injectors are wired to.

I did have a hard drive failure last year, and as noted, some things were lost, including the MS Flyback Photos I had. The text instructions should be "good enough" for most users.


Hope this helps everyone!
Hardwyre
Experienced MS/Extra'er
Posts: 293
Joined: Thu Dec 23, 2010 10:11 pm

Re: MegaSquirt Flyback Modification

Post by Hardwyre »

Interesting, a good deal more in depth then simply lifting the middle legs of Q9 and Q12, but it also puts the batt sense on a cleaner line. Thanks!
My Datsun is powered by: Pick'N'Pull, Cadillac, BMW, Ford, HomeDepot, Volvo, etc, etc.
Image
A MSExtra success story! http://www.msextra.com/forums/viewtopic ... 04&t=40364
MadMike
MS/Extra Newbie
Posts: 8
Joined: Wed Jun 08, 2011 10:16 am

Re: MegaSquirt Flyback Modification

Post by MadMike »

This jumper can be routed under the MAP sensor.

Alternatively, the jumper can be attached from the top of trace to pin 6 directly.

Image LOST.

Install a 0.001uf capacitor into the bootloader header.

If C12 is provided with the kit, and isn't used in the stock location, it can be used here.

Image LOST.

IMPORTANT!!!

IMPORTANT!!!

Run a 18-16g wire from the connector DB37 pin6, through a 5A fuse, to the same physical connection that the injectors are wired to.

I did have a hard drive failure last year, and as noted, some things were lost, including the MS Flyback Photos I had. The text instructions should be "good enough" for most users.
So everything up to here seems pretty clear. What about the rest??? Last pic is the back side of the board where we tapped into R3. Right?
Install a 0.001uf capacitor into the bootloader header.
I don't get what is the bootloader header?
Run a 18-16g wire from the connector DB37 pin6, through a 5A fuse, to the same physical connection that the injectors are wired to.
I get DB37 pin6 w/ 5amp fuse to what?? Is there a pin # or some identifier? Or are we just talking about the wire going to the injectors thru the DB37 ? A little unclear since everything that was talked about was in the box.

I know it's kind of a newb question. I think this is a good article, but it could use a little clarification and maybe the missing photos. Please remember It is easy when you already know the answer I don't.

Thanks for your time.
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