MS1 Single Coil wiring

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grayfoxx
MS/Extra Newbie
Posts: 9
Joined: Sat Oct 22, 2016 10:29 pm
Location: Rogue Valley, Oregon

MS1 Single Coil wiring

Post by grayfoxx »

Hey Guys,

I'm a noob so please be kind. I'm installing a brand new MS1 v2.2 on a 3cyl 800cc HUIHAI motor. It has a single coil with distributor. I am following this guide using a BIP373 http://www.msextra.com/doc/ms1extra/Diz ... ut_v22.htm . I'm a little confused about this line " It is good practice to provide the coil its own ground return by twisting a ground wire (pin 25, 27) together with the live coil wire (pin 29, 31)." I assume this means a twisted, insulated pair simply to prevent crosstalk? Also, where would I connect the hall sensor out of the distributor to the MS?

Thank you!
Roketa GK-25A
800cc
3cyl
EFI
Single Coil Ignition/Distributor
Megasquirt 1 v2.2 - hi-res 11d FW
grayfoxx
MS/Extra Newbie
Posts: 9
Joined: Sat Oct 22, 2016 10:29 pm
Location: Rogue Valley, Oregon

Re: MS1 Single Coil wiring

Post by grayfoxx »

To expand on my question, could I not simply run Pin 1 of the BIP373 to R25 then run pins 2 and 3 straight out of the case to the coil and chassis ground respectively? What exactly do I gain from passing through X11,12,13, and 14?
Roketa GK-25A
800cc
3cyl
EFI
Single Coil Ignition/Distributor
Megasquirt 1 v2.2 - hi-res 11d FW
slow_hemi6
Super MS/Extra'er
Posts: 4122
Joined: Fri May 07, 2004 3:33 am
Location: Australia

Re: MS1 Single Coil wiring

Post by slow_hemi6 »

You still have to have the 330 ohm resistor between pin1 of the BIP373 and R25. All that is gained by using the X pins is a single point of disconnect and an element of neatness to the install, if that is something that concerns you. I have one ecu where I have 4 x BIP373 and they are mounted in a separate enclosure in the engine bay. Only the Pin1 signal wires go back to the ecu. I have another where I have 3 BIP373 installed inside the ecu and the coil and ground wires come out on a DB9 I installed on the case end.
Your hall input will depend a bit on the type and operation of the hall sender. Is it open collector ground switching or does it have an in built pull up?
Find the Manuals up top under Quick links: Manuals. :RTFM:
Cheers Luke
preludefan
Helpful MS/Extra'er
Posts: 48
Joined: Thu Sep 20, 2007 10:24 pm

Re: MS1 Single Coil wiring

Post by preludefan »

Hi,

x11, thru 14 are PCB tracks that go direct to the pins on the db37- i used a non 90 degrees DB37 on mine so i could go direct to the external pins, but that involved ALOT of work.
The reason you need to tie pin 25 and 27 etc together is if you are installing the BIP373 INSIDE your megasquirt case, individually, each output pin 5 A max cannot carry the current for anything hefty like injectors or coils, they have to be doubled up.
If you want to avoid this, you could use and externally mounted ignitor fitted under your hood and use a single output that way.
remember if using the bip373 to always use the 330 ohm resistor.

I hope this answers your question :D

Mike
grayfoxx
MS/Extra Newbie
Posts: 9
Joined: Sat Oct 22, 2016 10:29 pm
Location: Rogue Valley, Oregon

Re: MS1 Single Coil wiring

Post by grayfoxx »

Thank you guys for the answers. I used the resistor on my BIP. I opted to skip the X pins and just passed the ground and coil wires out through two freshly drilled holes in the case. As for the Hall sensor I have to believe it does not have a built in pull up. I was unable to get signal when connected to MS in any wiring pattern of the three hall sensor wires. I tried an LED test and a dmm test to see if I picked up voltage when the distributor rotated and also with a magnet and metal plate. I get nothing whatsoever. I'm guessing I need a pull up or the sensor is bad.
Roketa GK-25A
800cc
3cyl
EFI
Single Coil Ignition/Distributor
Megasquirt 1 v2.2 - hi-res 11d FW
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