Maxima COP Triggering

http://www.diyautotune.com
Post Reply
Spoolin6er
Dreams of owning a 240!
Posts: 95
Joined: Tue Jul 03, 2012 2:30 pm

Maxima COP Triggering

Post by Spoolin6er »

I found this write up, but it is for the PNP MS, and I am running MS1 v3.0 board so I wanted to clarify something:

I am not sure what the Spark A and B outputs really are (if they are conditioned) on the PNP ECU. Can the maxima coils be driven directly from the LED's? Aren't those LED's always powered and then the transistors (Q6 and Q8) switch to ground to light them?

Or do the coils need a 5v pull up like this?:
http://www.msextra.com/doc/ms1extra/MS_ ... htm#5Vpull

Thanks for the help!
Last edited by Spoolin6er on Sun Apr 05, 2015 1:31 pm, edited 1 time in total.
Kill3rwill
240sx Wannabe
Posts: 118
Joined: Sat Aug 17, 2013 10:38 am

Re: Maxima COP Triggering

Post by Kill3rwill »

EDIT: i am an idiot who didnt read. i dont believe the DIY boards come with the necesarry outputs from the factory. the MSPNP's use a microsquirt module, but i think you can buy the add on board to run wasted spark.
Spoolin6er
Dreams of owning a 240!
Posts: 95
Joined: Tue Jul 03, 2012 2:30 pm

Re: Maxima COP Triggering

Post by Spoolin6er »

Thanks for the quick reply, but I'm pretty sure I don't need a daughter board to get this to work... worst case I need to build a pull up circuit.
User avatar
Matt Cramer
KA-T.org Sponsor
KA-T.org Sponsor
Posts: 934
Joined: Mon Sep 15, 2008 5:34 am
Contact:

Re: Maxima COP Triggering

Post by Matt Cramer »

You will need to modify the ECU for two 5 volt logic level outputs.

http://www.msextra.com/doc/ms1extra/MS_ ... .htm#cop30

Either the "5V Pull Up to fire" or "Ground switching" mod on that page can work.
Matt at DIYAutoTune.com - Megasquirt ECUs, fuel injectors, wideband O2 sensor systems, and more
Nissan plug and play engine management now in stock!
Spoolin6er
Dreams of owning a 240!
Posts: 95
Joined: Tue Jul 03, 2012 2:30 pm

Re: Maxima COP Triggering

Post by Spoolin6er »

interesting. So the pnp ms2 (found in this thread: http://www.ka-t.org/viewtopic.php?f=2&t=60105 ) already has one of those circuits built in an output on pin 2 and 3 of the expansion DB15? Which circuit does it use? I'd like to emulate that since its known to work.

(sorry, realized i some how missed putting the write up link in my first post. Now edited.
User avatar
Matt Cramer
KA-T.org Sponsor
KA-T.org Sponsor
Posts: 934
Joined: Mon Sep 15, 2008 5:34 am
Contact:

Re: Maxima COP Triggering

Post by Matt Cramer »

As the MSPNP is based on the MicroSquirt Module, it does not quite fit any of these categories. Its output circuit is most closely related to the "5V Pull Up to Fire", but is not an exact match.
Matt at DIYAutoTune.com - Megasquirt ECUs, fuel injectors, wideband O2 sensor systems, and more
Nissan plug and play engine management now in stock!
Spoolin6er
Dreams of owning a 240!
Posts: 95
Joined: Tue Jul 03, 2012 2:30 pm

Re: Maxima COP Triggering

Post by Spoolin6er »

interesting. Can you explain the difference? Is there any reason that using the pull up circuit might not work in place of the microsquirt output?
User avatar
Matt Cramer
KA-T.org Sponsor
KA-T.org Sponsor
Posts: 934
Joined: Mon Sep 15, 2008 5:34 am
Contact:

Re: Maxima COP Triggering

Post by Matt Cramer »

We are using a variant of the "5V pull up to fire" circuit that has been adapted to the MicroSquirt Module and has a 22 ohm resistor added inline to prevent killing the transistor if the output is shorted to ground.
Matt at DIYAutoTune.com - Megasquirt ECUs, fuel injectors, wideband O2 sensor systems, and more
Nissan plug and play engine management now in stock!
Spoolin6er
Dreams of owning a 240!
Posts: 95
Joined: Tue Jul 03, 2012 2:30 pm

Re: Maxima COP Triggering

Post by Spoolin6er »

So tried to start it up last night with the new COP's. When I turned the key to ON the coils got hot. I was using Spark Inverted = Yes as the how to suggested (link in previous post). I switched it to NO and the coils aren't getting hot, but the engine won't start. (Didn't try to start with inverted = yes)

Is there any reason why the PNP would use inverted=Yes, and i would need to use inverted=NO? Trying to figure out if its related to my engine not starting (seems to try and start but the timing sounds off, still working on checking that)
User avatar
Matt Cramer
KA-T.org Sponsor
KA-T.org Sponsor
Posts: 934
Joined: Mon Sep 15, 2008 5:34 am
Contact:

Re: Maxima COP Triggering

Post by Matt Cramer »

The MSPNP is set up so that "Going high" means it sends a 0 volt signal when off and 5 volts when dwelling the coil. Some circuits in the MS1/Extra manual use the opposite logic.
Matt at DIYAutoTune.com - Megasquirt ECUs, fuel injectors, wideband O2 sensor systems, and more
Nissan plug and play engine management now in stock!
Spoolin6er
Dreams of owning a 240!
Posts: 95
Joined: Tue Jul 03, 2012 2:30 pm

Re: Maxima COP Triggering

Post by Spoolin6er »

Interesting, I am using this circuit: http://www.msextra.com/doc/ms1extra/MS_ ... htm#5Vpull

Which if i'm reading correctly "goes high" when dwelling the coils correct? Unless i did something horribly wrong.

I bring this up because I am apparently doing something wrong with these coils. While trying to start I am getting controller resets to the point that it won't stay running. I assumed it was my power wiring or noise in that wiring so I have wired the MS and CAS power to a completely separate 12v power source for trouble shooting. And I still got controller resets. So i unplugged the coils - NO more controller resets...

Thoughts?
User avatar
Matt Cramer
KA-T.org Sponsor
KA-T.org Sponsor
Posts: 934
Joined: Mon Sep 15, 2008 5:34 am
Contact:

Re: Maxima COP Triggering

Post by Matt Cramer »

That circuit needs to be set to going low.
Matt at DIYAutoTune.com - Megasquirt ECUs, fuel injectors, wideband O2 sensor systems, and more
Nissan plug and play engine management now in stock!
Spoolin6er
Dreams of owning a 240!
Posts: 95
Joined: Tue Jul 03, 2012 2:30 pm

Re: Maxima COP Triggering

Post by Spoolin6er »

Matt Cramer wrote:The MSPNP is set up so that "Going high" means it sends a 0 volt signal when off and 5 volts when dwelling the coil. Some circuits in the MS1/Extra manual use the opposite logic.
Can you clarify this? I have read elsewhere that going high means that 0v charges the coil and then when the signal goes back high it fires? Does this going high/low terminology differ from coils to coil and/or MS version?

Any thoughts on how my coils being plugged in could be causing resets?

Thanks
User avatar
Matt Cramer
KA-T.org Sponsor
KA-T.org Sponsor
Posts: 934
Joined: Mon Sep 15, 2008 5:34 am
Contact:

Re: Maxima COP Triggering

Post by Matt Cramer »

Going low vs going high refers to what the MegaSquirt is doing at the processor pins. Some output circuits reverse what actually happens to the signal by the time it makes it to the harness. The MegaSquirt CPU is not aware of what circuitry may be downstream of the processor pins.
Matt at DIYAutoTune.com - Megasquirt ECUs, fuel injectors, wideband O2 sensor systems, and more
Nissan plug and play engine management now in stock!
Spoolin6er
Dreams of owning a 240!
Posts: 95
Joined: Tue Jul 03, 2012 2:30 pm

Re: Maxima COP Triggering

Post by Spoolin6er »

Ah,I see where I was getting confused. Thanks.

Any ideas why having my coils plugged in would cause resets that don't occur when I unplug them?

I even powered/grounded the MS from a separate 12v source to try and eliminate possible noise or cranking voltage drop issues and I have the same problem... :(
Spoolin6er
Dreams of owning a 240!
Posts: 95
Joined: Tue Jul 03, 2012 2:30 pm

Re: Maxima COP Triggering

Post by Spoolin6er »

No ideas on the resets?
User avatar
Matt Cramer
KA-T.org Sponsor
KA-T.org Sponsor
Posts: 934
Joined: Mon Sep 15, 2008 5:34 am
Contact:

Re: Maxima COP Triggering

Post by Matt Cramer »

It could be that the way you built your circuit was feeding so much power to the coils that the voltage would dip unacceptably low. Try a 100 ohm resistor inline with the spark outputs.
Matt at DIYAutoTune.com - Megasquirt ECUs, fuel injectors, wideband O2 sensor systems, and more
Nissan plug and play engine management now in stock!
Post Reply