New wasted spark coil w/drivers (beta)

[KneipeMeijer]

Thanks varg for the clarification, wired the signal ground directly to the main ground on the ecu and got it working only thing left is to fabricate a bracket for the coil.

[varg]

A "switched" ground would be something you wire in or an ECU function. It's common to ground the coil of a relay to turn it on when fused 12V is easily available near the relay, and the ECU grounds the fuel injectors to fire them, for example. It's often preferable to switch relays by switching ground because you can run a wire to any chassis ground in the cabin to the switch then through the firewall to the relay with zero risk of ever grounding out a +12V and less effort than finding one to splice into.

Signal ground on the internally driven coil is just grounding the "signal -" on the coil driver transistors to the ECU ground plane to avoid noise and differences in ground potential between the ECU and coil primary ground either via wire resistance or ground connection resistance. With megasquirt for example that signal - would go to any generic ground wire pin or directly to ground plane. You'd wire in a 4+ pin auxiliary connector with a signal - to some ground plane position on the board, and the 3 outputs necessary to control the coil drivers. Take notice that with the car running, if you were to take your multimeter and measure voltage between the ECU ground plane and the strut tower ground for example, you may not see zero, this is why you ground a sensor or a coil driver to the ECU directly.

[KneipeMeijer]

I didn't think there was such a thing as "Switched" ground. The ground is grounded all the time, whether power is on or off. So i looked up "Signal" ground vs "Chassis" ground. It looks like the only difference is "Signal" ground is usually on the ECU and just a cleaned up ground with no noise, but eventually connects to the chassis ground anyway. So I would think any ground on your ECU would work. Your switched power should be coming from the coil switched power wire.

That's what I thought but I am not sure, everything else is connected except the signal ground.

[Hoffbrohaus]

Got the coils working yesterday, The only problem is that i took the switched ground from the fuelpump which is not ideal because now the fuelpump keeps running when the key is turned to the on position. The only problem i got is that i cant find a switched ground which is not used, does it need to be a switched ground or could i take a main ground from the ecu?

Uhh we might need varg on this one. I didn't think there was such a thing as "Switched" ground. The ground is grounded all the time, whether power is on or off. So i looked up "Signal" ground vs "Chassis" ground. It looks like the only difference is "Signal" ground is usually on the ECU and just a cleaned up ground with no noise, but eventually connects to the chassis ground anyway. So I would think any ground on your ECU would work. Your switched power should be coming from the coil switched power wire.

Primary + (Switched power from coil)
Primary - (Chassis ground)
Signal - (ECU ground)
Signal a + (ECU)
Signal b + (ECU)
Signal c + (ECU)

[KneipeMeijer]

Got the coils working yesterday, The only problem is that i took the switched ground from the fuelpump which is not ideal because now the fuelpump keeps running when the key is turned to the on position. The only problem i got is that i cant find a switched ground which is not used, does it need to be a switched ground or could i take a main ground from the ecu?

[Hoffbrohaus]

Alright got the coil today, I am trying to install it into my k-data (KDFI 1.4) ecu. Hope Hoffbrohaus could confirm.

Confirmed and what varg said. I took the coil wires and taped the coil ground wire off. (previously i did that wrong and fried the board) Then I ran Primary+ to the switched coil power wire.

The Primary- then ran to the chassis ground on the shock tower.



all the rest, 4 wires, I fed through the firewall into the glovebox to run to the ecu. Signal- (black) is going to "signal ground" pin 22 on the mspnp2.

[KneipeMeijer]

Alright got the coil today, I am trying to install it into my k-data (KDFI 1.4) ecu. Hope Hoffbrohaus could confirm.

[varg]

So for what i understand is
Primary + (Switched power from coil)
Primary - (Chassis ground/ battery ground ?)
Signal - (Negative wire coil ?)
Signal a + (ECU)
Signal b + (ECU)
Signal c + (ECU)

Could someone confirm this?

Signal - should go to the ECU ground plane but yes, it's triggered by a switched +5V signal. Or at least it's typical of most logic level signal controlled coils. If this one is different for some reason hoffbrohaus can correct me.

[KneipeMeijer]

GM ignition coil from their V6 models, maybe DIY has characterized them for dwell vs amperage and output. Like GM's LS coils, it'll have internal driver circuitry from the factory. Typically if it has 4 pins for one coil it has an internal driver, this follows that logic with 6 pins for 3 coils.

• primary +
• primary -
• signal -
• signal a +
• signal b +
• signal c +

So for what i understand is
Primary + (Switched power from coil)
Primary - (Chassis ground/ battery ground ?)
Signal - (Negative wire coil ?)
Signal a + (ECU)
Signal b + (ECU)
Signal c + (ECU)

Could someone confirm this?

[KneipeMeijer]

Hey guys i have a question where does the black and white wire go?

[Hoffbrohaus]

Ok got my MSPNP2 back fully repaired. Made sure my stock coil ground wire was fully insulated and separated from the power wire. Car is back up and running well. Looks like this coil pack works after all. I'll try to find out from DIYAuto what makes thier version special because it looks like you can buy these anywhere for $90 sans wire harness.

[Hoffbrohaus]

DIYAuto got back to me and said they think it was user error. That somehow the stock coil ground wire shorted the board. I taped that ground wire but I guess not good enough. So there shouldn't be a problem with this setup after all. They repaired my MSPNP and I'm just waiting to get it back.

Their diagnosis:
"Stock coil negative grounded when coil removed, causing Ign output trace to burn. This in turn lead to internal arcing in ECU from the damaged high current ignition trace, shorting out the CEL output."

[ADEN]

Thank you, great insight. I sent my PNP in to DIY for diagnosis/repair for free since I am beta testing for them. I will let them know your input as I do not think the MSPNP2 has built in ignitors and you are correct in saying I'm using logic outputs. The engineer from DIY originally said "I have some samples of a LOGIC driven 6-cylinder wasted spark coil pack that you can just wire up to the PNP ECU directly," So that sounds exactly like what you are saying.

Now are you saying the ignition outputs on the MSPNP2 can get damaged because they can't handle the 3amps coming from the coil pack?

In my logic (Arduino) you shouldn't be drawing more than 200ma for all digital and pwm outputs, That's why in Speeduino they using something called logic driven IGBTs (MOSFETs) that draw around 20ma each to drive dump and smart coils.

So in your case with ford coil pack that we use they are not recommended to drive them directly from logic due to them drawing between 60 to 200ms and also to prevent EMI reaching the logic, That's why most board designers use mosfet drivers like TC4424 between logic and ignition output (see picture).

[Hoffbrohaus]

I am running those coils on my m20 along with Speeduino they are good so far i removed the ignitors from the board since the coil pack has internal ignitors only added 2 of TC4424EPA so output amperage raised from Arduino (direct) 100ma to 2a i guess.

I first ran 3.5ms Dwell time but i went down to 1.8ms and still running smooth i kept it at 2ms so the coils don't get hot.

Do you have ignitors in the board? Or running straight from the logic? I believe in your case you are running them straight from the logic output that might damage the logic ignition outputs.

Disconnect the coils and connect your laptop then activate the 3 (1-2-3) ignition outputs to 100% in the hardware test put positive probe of you voltmeter on each output and ground probe to any main board ground point if readings below 4.9V-4.8V then logic will have a problem charging the coils probably replace it.

Thank you, great insight. I sent my PNP in to DIY for diagnosis/repair for free since I am beta testing for them. I will let them know your input as I do not think the MSPNP2 has built in ignitors and you are correct in saying I'm using logic outputs. The engineer from DIY originally said "I have some samples of a LOGIC driven 6-cylinder wasted spark coil pack that you can just wire up to the PNP ECU directly," So that sounds exactly like what you are saying.

Now are you saying the ignition outputs on the MSPNP2 can get damaged because they can't handle the 3amps coming from the coil pack?

[ADEN]

Yea my Mspnp2 is about 1 month old. And since I'm testing this coil with logic driver s built in I would think that has to be it.

One random thing that I don't think could have done anything. I cut off the pulse sensor wire that was hanging on the number 6 plug wire since I don't need it anymore. I couldn't get the ring off the wire. That's not causing an arc between the plug wires or something right?

I am running those coils on my m20 along with Speeduino they are good so far i removed the ignitors from the board since the coil pack has internal ignitors only added 2 of TC4424EPA so output amperage raised from Arduino (direct) 100ma to 2a i guess.

I first ran 3.5ms Dwell time but i went down to 1.8ms and still running smooth i kept it at 2ms so the coils don't get hot.

Do you have ignitors in the board? Or running straight from the logic? I believe in your case you are running them straight from the logic output that might damage the logic ignition outputs.

Disconnect the coils and connect your laptop then activate the 3 (1-2-3) ignition outputs to 100% in the hardware test put positive probe of you voltmeter on each output and ground probe to any main board ground point if readings below 4.9V-4.8V then logic will have a problem charging the coils probably replace it.