Androo

So I'm still working on my weird ignition problem and decided to replace my suspect 2nd hand Toyota COPs with some brand new pukka NGK Audi R8 ones.

Now I've got no spark. What did I do wrong?

The coils I bought are part no U5014 - 48041

I previously had Toyota COPs set up like this: Upgrading to Coil on Plugs (all years) COP writeup - Miata Turbo Forum - Boost cars, acquire cats.

I wired up my Audi R8 coils as described on here: R8 Coil wiring - G4+ - Link Engine Management Forums (linkecu.com)

So in changing from the Toyota COPs I changed the connectors to the VAG ones and kept all the pins in the same place, but with the wires at pin 3 on the Toyota plugs that previously went to the tach input wire (near where the ignitor used to be), I changed this so it goes to the ground wire near the ignitor and also grounded this at the cylinder head. I've also configured my Megasquirt so it outputs a tach signal at Pin 2I

So the pins on the Audi R8 coils are configured as follows (reading with pin no.4 on the left as you look at the socket on the coil, no.1 on the right):

Pin 4 - main ground
Pin 3 - ignition signal
Pin 2 - signal ground
Pin 1 - +12V

I'm confused as to why I now have no spark. There's a diagram on here that shows a different pin out: Mazda MX-5 COP/Coil-On-Plug Install – Motorsport Electronics (motorsport-electronics.co.uk) although that webpage also contradicts itself and shows a pin out for the coils that is consistent with the above Link EM forum.

I've tried to find a definitive source of info for the R8 coil pin outs, but can only find forum posts for this.

Anyone got any ideas what I've done wrong?

der_vierte

Try a 1k Ohm resistor between the signal and 12v source, report back

Androo

Ah, fudge - Dimitris at MSLabs has confirmed that my MS3Mini V1 won't work with R8 coils.

I'll have to find some other solution - maybe time to look into LSx coils...

SpartanSV

Stock coils with iridium NGKs have taken me over 240kpa. Did you actually reach a point where the stock coils weren't enough?

Androo

I was having some issues which probably weren't related to the coils, but thought they were at the time. So I made the change to Toyota COPs and gutted the ignitor as part of the conversion. However the Toyota COPs haven't been good - if I still had an ignitor I'd go back to stock. But because I don't I'm looking to change up to something stronger.

I've ordered some D585 coils and will fab up some brackets to mount them (it'll be a fun little project - provided I can get them working okay)

jetskibruce

I was able to lay the coil with a plug on the valve cover and use test mode to check the vags I put in. I really like them, I had a lot of miss fires with older stock coils. It sounds like you have them wired ok, I used the same reference web site. I’m using .8 as the dwell with a bump up in boost. I had an odd problem too, before they started working, so I started testing out of the cylinder until I got spark and haven’t looked back. I have ms3pnp let me know if you want to know any particular setting I am using. I never really figured out what exactly I changed that finally got them firing, but since they have been flawless.

jetskibruce

The power and ground need to be good connections. I think I ran a wire with the signal ground back to near the mega squirt and included with the other grounds.

Androo

Just for closure to this thread, the issue was that my MS3 Mini (from MSLabs) is an early version (V1.0) and won't run the Audi R8 coils. Changed back to Toyota ones and its sparking again.

fastivab6tg25mr

I ran into a similar issue with MS3X trying to drive the R8 coils on my turbo FE3N. I ended up building the FET circuit in the proto area but if you put together that same FET driver circuit on a breadboard and ran it externally with the appropriate powers and grounds there's no reason it wouldn't work.