Spark out to MSD

[jacobnhra]

Hey guys,

I have a v2.2 pcb with a ms-2 cpu loaded with the latest firmware 3.2.4. The mega manual shows to run my output signal through a 2N2222A transistor from JP1 to the white MSD wire.(http://www.megamanual.com/ms2/index.htm)

On msextra.com they show that you can run straight from JP1 to my white MSD wire.(http://www.msextra.com/doc/ms2extra/MS2 ... on.htm#msd)

Which is safest and or the correct way to do this. I am using a GM 4 pin module with my msd pro billet distributor this is why I originally referenced the mega manual although I do realize its out of date now. If I can just jumper one wire and not fool with the transistor I would like to simplify it. Also does this have anything to do with the JS10/D14 spark output option in tuner studio? I am currently wanting to jumper this to pin 30 as I am not using a fast idle valve.

thanks,
Jacob

[SymTech Laboratories]

Some information in the MegaManual is out of date, and other information simply isn't applicable to MS/Extra systems. To connect your MS2/v2.2 system to an MSD ignition, follow the instructions here and connect the negative side of D17 to X12. Then connect the DB37 pin that corresponds to X12 to your MSD ignition.

http://www.msextra.com/doc/ms2extra/MS2 ... .htm#msd22

When you select the output in TunerStudio, be sure to select D14 (this is the v3.0 board equivalent to D17 on v2.2 boards).

[jacobnhra]

Thanks for the reply. I guess I left out some information. I'm using the JS10 for spark A out as I've used my X11-14 for my stepper motor. I guess my question would be if I could hook my jp1 port directly to msd through pin 30 of the db34 via removing the fidle transistor? Or does this need to be routed through a transistor as stated in the mega manual to be safe?

sorry to be a pain I'm just wanting it to be right and there isn't a lot of direct information on using ms-2 w/wo extra code on a v-2.2 pcb. Some of its vague, If I could purchase a v3.0 or 3.57 with components aside from the cpu I probably would just seems like a lot of extra expense for what little of it I'll use if i buy a complete kit.

Thanks'
Jacob

[jsmcortina]

Do not connect "JS10" (JP1/6) directly to an MSD box or you'll damage your MS2 card. That's why the manuals say to connect to D14 (LED17)
If you want to route it out through the DB37 on a different pin that's fine.

James

[jacobnhra]

would it suffice to just snip the led -lead and hook directly to the pcb pad or should I just solder directly to the led -lead?

[SymTech Laboratories]

would it suffice to just snip the led -lead and hook directly to the pcb pad or should I just solder directly to the led -lead?

It's easiest just to solder directly to the LED lead.

[jacobnhra]

Ok so I'm probably going to use the D14 output option but just to get back to my original question a little. If you built the circuit stated in the standard mega manual wouldn't you be doing the same thing as whats actually on the 2.2 pcb for D17 led? Or is it the idea that the D14 output is more robust than the JS10 output?

[SymTech Laboratories]

Ok so I'm probably going to use the D14 output option but just to get back to my original question a little. If you built the circuit stated in the standard mega manual wouldn't you be doing the same thing as whats actually on the 2.2 pcb for D17 led? Or is it the idea that the D14 output is more robust than the JS10 output?

The MegaManual suggests building a buffer circuit with a 2N2222 transistor, which is similar to the LED circuit. The buffer circuit is controlled by JS10 because that's the only available spark output with the B&G firmware. Rather than adding superfluous hardware, the MS/Extra firmware allows you to use the LED circuits as spark outputs.

If you're wondering why you can't use JS10 directly; it's a bad idea to connect any external devices directly to the processor. In this case, there are currents and voltages that the processor can't handle.

[jsmcortina]

Symtech are correct.

But also, the MSD white wire is connected to 12V via a 100 ohm resistor (or similar) so it would be sending a "stiff" 12V feed into the JS10 (JP1/6) connection which would almost certainly destroy your MS2 processor. Don't do that! Use the wiring the MSEXTRA manual.

James

[LEMCO_Novi_2000]

jsmcortina,
I too am trying to drive a MSD 6A from a V2.2 with the 32 bit daughter board from pin 30 of the DB-37. I re-biased Q-5 (the 2N2222A that was for sinking fast idle solenoid current) with a 4.7 K ohm resistor by pulling D-9 and putting one end of the resistor to the D-9 anode pad and the other to a through hole land connection for VCC (5V) just above where the diode was. Though it did indeed produce a 5v signal on the scope it still didn’t cure the erratic signal I get.

I first noticed this issue in the car when the timing light was dropping out and though I could see it on my O scope when I hooked it up, I thought it was just noise. Engine idled rock solid at 800 RPM with 20 degrees of advance (where the distributor is set) when I went back to using a VR to trigger the ignition module. When changing out the signal cable to the ignition module to twisted pair grounded at each end failed to help I pulled the MS and set it up on the bench with the scope, a laptop with TS, the simulator, and even a spare MSD 6A powered from a car battery with a coil and a spark plug.

The signal I get is especially bad around 1400 RPM. The periods of the wave-forms become inconsistent and un-useable. All I have to do is hook an LED up to pin 30 to see how erratic the signal is. I don’t get it. I set all the parameters as the manual instructed. I even changed the max coil duration to 25.5 in the .ini file and in the dwell menu.

I hate to put the weights back in my dual pickup MSD Billet again because being free of them was my main reason for up-grading the MPU but; at this point I don’t know what else to do. Is that what you did or did you get yours to work? TS must have changed since you posted because there is no menu for J-10/diode selection anymore.
LEMCO_Novi_2000

[Matt Cramer]

jsmcortina,
I too am trying to drive a MSD 6A from a V2.2 with the 32 bit daughter board from pin 30 of the DB-37. I re-biased Q-5 (the 2N2222A that was for sinking fast idle solenoid current) with a 4.7 K ohm resistor by pulling D-9 and putting one end of the resistor to the D-9 anode pad and the other to a through hole land connection for VCC (5V) just above where the diode was. Though it did indeed produce a 5v signal on the scope it still didn’t cure the erratic signal I get.

I first noticed this issue in the car when the timing light was dropping out and though I could see it on my O scope when I hooked it up, I thought it was just noise. Engine idled rock solid at 800 RPM with 20 degrees of advance (where the distributor is set) when I went back to using a VR to trigger the ignition module. When changing out the signal cable to the ignition module to twisted pair grounded at each end failed to help I pulled the MS and set it up on the bench with the scope, a laptop with TS, the simulator, and even a spare MSD 6A powered from a car battery with a coil and a spark plug.

The signal I get is especially bad around 1400 RPM. The periods of the wave-forms become inconsistent and un-useable. All I have to do is hook an LED up to pin 30 to see how erratic the signal is. I don’t get it. I set all the parameters as the manual instructed. I even changed the max coil duration to 25.5 in the .ini file and in the dwell menu.

I hate to put the weights back in my dual pickup MSD Billet again because being free of them was my main reason for up-grading the MPU but; at this point I don’t know what else to do. Is that what you did or did you get yours to work? TS must have changed since you posted because there is no menu for J-10/diode selection anymore.
LEMCO_Novi_2000