[Wlad]

You certainly can run the VR signal directly to a signal conditioner on your PCB

Does the "Mini MAX A2" conditioner works OK with the GM Distributors VR output ?

a separate coil driver will be needed

I suffered a lot with my GM trucks, all the 7/8-pin Ignition Modules that I can find near me are crap "Made in China",
and I keep having trouble over and over again with them
I'm willing to make my own ignition "coil driver" pcb just to have some piece of mind...
Is there any diagram that you know, that will work with the e-core coils of the GM HEI ignition system ?

[Izzy46]

I have suffered too with these ignition modules, I think this will be my forth module in around 100 hours of boating. The local boat mechanic always checks this first if a boat fails to show spark.

I'm also interested in going down the DIY coil driver in the future. I don't know of any that are in production at the moment though.

For now I'd like to get the boat running in a basic format before looking into a coil driver.

[PSIG]

Does the "Mini MAX A2" conditioner works OK with the GM Distributors VR output ?

I've only tested the MiniMax-A2 once on a GM HEI distributor VR pickup, but it worked well.

I'm willing to make my own ignition "coil driver" pcb just to have some piece of mind...
Is there any diagram that you know, that will work with the e-core coils of the GM HEI ignition system ?

Yes, search here for coil driver and igniter circuits like this. I used to build my own for fun, but it is so much easier and typically more reliable to use a factory unit. Any of the many modules out there in the wrecking yards or online, such as the J121, J701, PRW-2, or Bosch "034", etc.

The J121 is one of my favorites (random example), as they are everywhere (usually found on single-coil Mitsu, Suzuki, Ford, Mazda, Mercury, Geo, etc. pretty much late '80s to late '90s) and I've never seen one fail. All typically under $20 online, or next to free (with connector) at the wrecker's. I have collected a box full of them, as they are the simple and easy solution, for me anyway. If no connector, use 2.8mm spade connectors or just solder the wires to the pins. Also multi-channel ones for single or multi-coil setups.

BTW - @Flood posted a GM 8-pin HEI wiring example here. Again, the power ground is through the mounting holes, so get good ground there - and use heat sink paste on the metal back to the mount to get the heat out.

[Wlad]

but it is so much easier and typically more reliable to use a factory unit.

Thanks for the idea, I will take a look at them...

the power ground is through the mounting holes, so get good ground there - and use heat sink paste on the metal back to the mount to get the heat out.

Things I learned about the GM 7/8-Pin modules over the years:
- always wipe clean and get a fresh HeatSink-Paste under the module
- always add a wire to the module GND bolt, and route the wire direct to a good and clean engine ground
- always use new spark plugs, wires, cap and rotors; if one of them fail, the spark may "jump" to the table inside the distributor, damaging the ignition module
- always check the connector of the ignition module, the terminals may get hot and melt
- (hard to do in 2022) avoid ignition modules "Made in China"

[Izzy46]

So Uncle Jeff finally delivered my package today. Instead of delivery just one module like I'd ordered he deliver 4!! So I set about testing the modules again following Wlad's advice to ground the connecting bolts directly and to clean the heat sink paste from the module and distributor.

Unfortunately the results where 100% identical between the original GM module and two of the new (Chinese) module I bought (there were no genuine modules in stock).

I took another video of my testing.
The multimeter is reading the voltage at the R pin.

https://youtu.be/qxNYJFxZNZw

I think my wife summed it up best when she said: 'That thing needs foreplay! You've discovered a female part!'.

With three different control modules all showing the same characteristics I'm not really sure where to look next?

Could it be a problem with my Speeduino software setup?
Could it be a problem with my Speeduino hardware setup, there is a section which is left empty on the board?

https://photos.app.goo.gl/KsTJ7pNuMYKRHMGr9

[PSIG]

Could it be a problem with my Speeduino software setup?

Could be. I don't see where you posted your tune. Please post the tune you are currently testing. Even better, take a log of your short session so we can see what Speeduino "sees". Always post both files together, and ZIPped is a good method. A log of the issue and the exact tune used to take it are usually the first requirement to troubleshooting.

Could it be a problem with my Speeduino hardware setup, there is a section which is left empty on the board?

Indeed, I cannot see your wiring clearly, there is no diagram of how you wired for testing, and do not know the board version you are using. Can't say. But, issues like this are typically simple "doh!" stuff.

It's interesting to note that when the B pin has 5v the C-coil pin will show 0v. When Speeduino is able to 'capture' the ignition signal (see video in previous post) the C-coil pin will show a signal of 2.5v. It seems that under the right conditions the setup kind of works however the 2.5v output would probably not be enough to fire the coil. …

Keep in-mind what each pin and function are supposed to do. The C terminal is used to ground the coil for dwell — not feed the coil voltage. Reading any voltage on it (usually VBAT when installed to run) is coincidental to its function to ground the coil. Review the module functions you are testing in your head, so the results don't mess with you. BTDT Sometimes I get so focused, I miss the big picture.

[Izzy46]

Yep, so I think it was a basic rookie mistake!! I reinstalled the firmware and updated the base tune to one of Apollard's initial tunes. Speedy detects the ignition every time. So thanks to everyone for your help and advice on this one, I'll try and test my assumptions more thoroughly in the future.

Now it's on with the rest of the setup. I'm going to go through the following playlist to get a better understanding of TunerStudio.
https://www.youtube.com/playlist?list=P ... zz8iCJDRF_

Then it's on to installing the harness and Speedy in the boat. Hopefully I can get a clean run at it