1NZ/1ZZ coils and 20V motors/igniter/coils

[70XIN]

PLEASE bare with me, and don't go telling me to buy aftermarket ECU's and all that bullshit, i'm not interested haha. I am trying to do COP/DLI with the stock ECU, with a 20V igniter, but WITHOUT a factory coil zapping away to provide the tach signal etc.

*************

Ok, so

On a standard 20V igniter, it has five wires:

IGT - a +5v signal from the ECU to tell it to do something
IGF - a confirmation signal to tell the ECU the coil fired and winning
Blk/Wht - 12V+
Blk - Tach
Blk/Brwn - ??? Grounds the coil to charge it, and releases the ground to discharge its' magic ???

On the coil it has two wires:

Blk/Wht - 12V+
Blk/Brwn - As above with the igniter, a 'grounding' wire???

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Now, on club4ag forums (and others), it's all the rage to use 1ZZ/1NZ coils - which have four wires:

IGT
IGF
Ground
12V

They simply splice into the IGT wire before the igniter, the 12V+ before the igniter, ground the coils to the body, and ditch the IGF wire. Now, these guys have mixed results - most of them who run the factory igniter only have problems with tacho's not working, and 5k rev limits ----- guys who run factory igniter AND coil (along with all the 4 1ZZ/1NZ coils) end up having a working setup, with a factory coil zapping away, shocking passengers and generally making a load of noise.


ANYWAY, this finally brings me to my question (holy jesus) - is there ANY way i can utilise the blk/brwn wire coming out of the igniter, with the 1NZ/1ZZ coils? This wire is clearly the reason that the 'only factory igniter' guys have problems - ae86 tacho's run off that negative/ground of the factory coil.

Like, can the 1ZZ/1NZ coil be run in the same fashion as a 20V coil? I.E - 12V spliced above the igniter, and the blk/brwn wire either hooked up to the IGT or the ground wire on the 1ZZ/1NZ coils?

Thanks guys, i am le tired, goodnight.

[70XIN]

Or am i slightly overthinking it, and i should wire up the 1NZ/1ZZ coils in the same fashion as the club4ag guys (splice into IGT and 12V+, ground all of the coils somewhere on the body), and then run that blk/brwn wire of the igniter to the exact same grounding point that the coils are using?

Love,
Seamsu

[Sam-Q]

I am heading out but have you seen the guide on here:

[70XIN]

Yes i have thanks, but it doesn't answer my question *sad face*

[jdm86gtz]

Your black/brown wire is actually black/orange and is the 12V ignition feed, and then the black/white wire is the coil triggering wire.

[munki]

It would work out as a batch fire system, but if you would be effectivly working the coils twice as hard as in something like wasted spark. weather it would run like this on the factory ecu is another question. I dont see why you would need the factory igniter unless the signals are wildly different from the coils. I dont see why you cant just use a tacho booster to give you the signal you need.

Saying this, I have setup a microtech with a 4x igniter and sr20 cops running batch and all was well.

[70XIN]

jdm86gtz - The black/brown (now that i look at it during the day, black/red) wire is definitely the grounding wire. The black/white wire splices into a thick black/orange wire further up the loom, so that will be the 12V ign.

And munki, there's no question the system works, i'm just asking how to retain that black/brown(red) wire with the 1ZZ/1NZ coils. I'm retaining the factory igniter because it'll keep things neat, and must have an inbuilt tacho booster.

[munki]

The brown wire you are talking about will be a common ground, It will connect to both the coil and the igniter and typically register 0v. On most older toyotas the tacho signal is taken from the low tension side of the coil. When the high tension side of the coil is fired a similar spike is seen through the low tension side (negative). This spike is taken directly by the tacho in the cluster and converted into movement, no igniter input is required.

Now in the COPs, you have a similar setup; There is the positive feed of the coil, a 5v signal wire and the IGF wire to tell the ecu that the ignition event was sucessful and it also helps determine dwell times. Then there is the common ground, like the factory blacktop igniter/coil setup. So obviously the feed for the tacho can be taken from here, BUT you need to be sure that the voltage spike from a single smaller coil is enough to register with the tacho dash, so a booster may be needed. This is simply a relay with a 12v feed acting as a signal amplifer.

If im totally off the mark let me know fever isnt helping too much atm.

[70XIN]

Yeah man, you're definitely on the right track, the guys in the states have tried tacho boosters and other such things, but still have the rev-limit/tacho problems - but i think they're just doing it wrong.

This will probably answer my question better - the factory ground wire coming out of the igniter (blk/red, 5th pin), would it be able to "read" the -ve voltage spike if it was attached to the same grounding point as the 1ZZ coil grounds? Or could i run the 1ZZ coil ground wires straight to this wire without grounding to the body (or is this unsafe/detrimental in some way??)?

Cheers
Seamus

[Nicko]

Could this be an internal ignitor vs external ignitor issue?