Igniter for use with Megasquirt

[Vertigo]

Sup, had a poke around Zebra today to look for a Mitsi dual channel igniter. Couldnt find any, but did find a pair of single channel ones, at least I think they are. Part numbers J5T 60572. They have GND, VB, IG+, and IG- pins. These should do the job for a wasted spark 4AGE? Im using 4AGZE dual coil packs.

[jondee86]

One of these, found on a number of Mitsis...



Or one of these, found on Legacy turbo wagons and others....



Cheers... jondee86

[Vertigo]

Yea the J722T is the one I wanted, but couldnt find even one! Ive since located on on Trademe, thatll do.

Would the J5T's do the job, thought?

[thegreatestben]

Just get the two channel, heaps of guys on here seem to frequent wreckers yards. They are really easy to grab.
I found one on a DOHC mirage at pap here in welly after looking for about 2 minutes.

Two will just complicate things.

[jondee86]

Would the J5T's do the job, thought?

Two single channel igniters will get you there; just means a bit more wiring.
The two channel version has a 12V square wave tacho output, if that is of
any use to you. Should drive an aftermarket tacho no problems.

Cheers... jondee86

[Vertigo]

Ideally I would take the tach output and run it strait to the factory tach. Would I need any translation between that and the J722T?

[thegreatestben]

If it's in an aw11 then yes. I had to make a small circuit which was very easy.

I think it's a haltech diagram.
http://img.photobucket.com/albums/v172/ ... dapter.gif

[jondee86]

http://www.msextra.com/doc/ms1extra/MS_Extra_Hardware_Manual.htm#tachoout

Cheers... jondee86

[Vertigo]

Great thanks. Found that page in my researching already, and decided to use that exact circuit. I presume -ve terminal is the control line from the ignitors?

[thegreatestben]

If you are referring to my diagram, it is literally the negative side of the coil which is the switched side.
The tach is showing the rate at which the coils are being switched on and off pretty much.

The standard AW11 tach reads only one coil, so when you change to dual coils it'd get the wrong signal.
That circuit doesn't use the ignitor to produce the signal for the tach at all.

[jondee86]

If you have a AUX out on your ECU that can be programmed as a TACHO and
can switch 12V to ground, you can use the Mode 2 diagram above. All you
need is the coil out of any small random relay found in a Toyota fuse box at
Pocket-Parts. Disable/discard/destroy the moving parts inside the relay, as
otherwise they will make a buzzing noise and annoy you after a while. Put 12V
on one side of the coil, and connect the other side to the AUX out and to the
tacho input wire.

Job done... no cost... works like a charm... I have it in my car

Cheers... jondee86

[Stu-]

Or you can change the resistor inside the tacho and not have to run any special wiring.

[Stu-]

Re-ignitors - there's several 4cyl mitsi's at Pick a Part west which would have the ignitor you need and likely have the seperate tacho interface too

[jondee86]

... and likely have the seperate tacho interface too

What does the interface do exactly ?

Cheers... jondee86

[Bazda]

Tach interface allows you to pick up a tacho signal. Which you can connect to the rev counter etc.
Thats how I run mine.

[Stu-]

As above, the come standard on some (but not all) mitsi wasted spark setups - little rectangle unit. Combines the high level signal from wasted spark coil outputs so you can run it direct to a tacho that normally runs from a single high level coil. They work ok, but sometimes they can be every so slightly slow to react - I always prefer to run the tacho from the ecu as its super accurate. Although 9 times out of 10 requires the resistor in the tacho to be changed - but its a easy job to do.

[matt dunn]

Quite often with the aftermarket tacho's like the VDO ones etc
they will not work correctly from the ECU generated signals and work better from a tach adapter.

[Stu-]

Good to know. I've only had to set up an autometer one for a customer and that was a high level drive, all the rest have been standard tachos which have worked well.

[Vertigo]

Honestly, I think Ill just go with the dual J5T's and making my own diode tach signal circuit. Seems easier and less error prone to me!

[Stu-]

Yep that will work and making the diode circuit is easy, just not as quick acting and sometimes slightly out from actual rpm.