Mitsi Igniter and Wasted Spark

[jondee86]

I got me one of these...



This is to run wasted spark with GZE coils and an aftermarket ECU. Now
looking at the old threads, I figure the tacho output will be fine to drive
my factory AE86 tacho. Just posted this up since it seems to be a popular
question

What I would like to know is where do I get a "rpm" signal to run my
RSM ?? It came off what I'm pretty sure was the IGF signal on the OEM
ECU. Any suggestions ?

Cheers... jondee86

[gasman]

i tried using the tach signal from a mitsi ignitor to run my tacho on my ae92 but it didnt work so ended up using a tacho interface as well tapped into the negative wires of the coil.

[Xyrath 86]

Yeah tach output from the ignitor didn't work on my 86 either.

This works though and is only about $1 worth of parts:

[QikStarlie]

yeh that misti ignitor will only run a a low level tach. might work on your rsm. have used the drawing above many times also, to run toyota tac's. works all good.

[deaf_rattle]

yeh that misti ignitor will only run a a low level tach. might work on your rsm. have used the drawing above many times also, to run toyota tac's. works all good.

all good for 5mge to 7mgte conversion as well, although obviously you need to adapt for extra coil...

[Quirky]

while we are on this topic, im running mitsi ignitors on my gze.

I just ziptied them to the strut bar, should they be grounded or something?

[thegreatestben]

They should be mounted to a flat metal surface and use a thermal grease/paste to transfer heat away from the ignitor itself.

Probably not great how you've got them

[Quirky]

They should be mounted to a flat metal surface and use a thermal grease/paste to transfer heat away from the ignitor itself.

Probably not great how you've got them

Sweet, thats the next 'modification'
Ive got an old video card cooler 20 cm of solid copper, ill stick the ignitors on to that.

Also, as for dash pickup, i swapped the tacho circuit board of the gze into the fxgt dash.

Probably hard to find if you didnt get one with your halfcut.

[AceSniper]

If you know what resistor to bridge behind your tacho you can make it run on the mitsi low level output on the ignitor....

Or use the setup image above(haltech).... But iv found it works a lot better with just diodes and don't input the 12v via the resistor at all as it causes the tacho to spike (on ae101 anyway)

[jondee86]

After doing a bit of research, it seems to be looking like this...

1. Mitsi igniter - put 12V in and get 12V square wave tach output.

EDIT: Looking at the Mitsi wiring diagram it is clear that Mitsi feed the
igniter 5V and get a 5V square wave out for the taco.

2. Coil negative tacho signal - 20 to 30V spike.

3. OEM ECU output IGT signal - 5V square wave.

4. OEM igniter output IGF signal - 5V sawtooth wave.

5. Aftermarket ECU tacho output - 5V square wave.

6. OEM AE86 igniter tacho input -

I also found this which takes a signal from each coil negative...

Perhaps someone could predict the output waveform/voltage ??

So, before I start messing with wires, does anyone know for sure what
signal the AE86 tacho needs to operate correctly ??

Cheers... jondee86

[thegreatestben]

Can you get the diodes for that haltech diagram from dick smith's or do I have to go somewhere like jaycar?

[sergei]

Can you get the diodes for that haltech diagram from dick smith's or do I have to go somewhere like jaycar?

It is the most common diode in use - should be in dick smith.

[QikStarlie]

yeh dick smith have all that stuff.

Or use the setup image above(haltech).... But iv found it works a lot better with just diodes and don't input the 12v via the resistor at all as it causes the tacho to spike (on ae101 anyway)

ground disconected you mean? there should be no 12v to that circuit

So, before I start messing with wires, does anyone know for sure what
signal the AE86 tacho needs to operate correctly ??

Cheers... jondee86

coil negative

[jondee86]

Righto... the collective wisdom of this forum, and the entire interweb,
has come down to this...

1. OEM AE86 igniter most likely outputs a coil negative signal with a
1kOhm resistor in series.

2. The diode solution seems to emulate this signal, so I shall try this
for my tacho signal.

3. 5V square wave should be OK for the RSM, so I will try hooking
this up to the aftermarket ECU "tacho" output.

When I have tried these setups I shall post up the results. Nothing like
some hard facts to kill a good argument

Cheers... jondee86

[thegreatestben]

I bought the parts for that diagram today.
Dick smith didn't have any of the bits except the resistors

Jaycar was open and I got enough parts to make two.

ZR1415 - 1N4744 x2 = $1.32
ZR1004 - 1N4004 x1 (pack of 4) = $0.60
Resistors = $0.60

If you want the mitsi ignitor to out put a square wave do either 1) or 2)


I tested that out and got my multimeter to pick up an RPM signal. As soon as I removed the power source (either 5v or 12v) I lost signal all together.

If I don't bugger it up I'll make two of the haltech circuits. if someone else wants one.

Here is the mitsi diagram for this type of ignitor:
http://i118.photobucket.com/albums/o97/ ... ires-1.jpg

[D0DGEE]

i got a mitsi ignitor on my car and just had to use a 1k resistor and 12v to one side of it and the other to the tacho and that worked fine but i am using a autometer tacho as my car dont have a factory tacho.

[gasman]

I bought the parts for that diagram today.
Dick smith didn't have any of the bits except the resistors

yea dicks smith has become useless like that. dont have any of the hard core stuff no more.

[jondee86]

i got a mitsi ignitor on my car and just had to use a 1k resistor and 12v to
one side of it and the other to the tacho and that worked fine but i am using
a autometer tacho as my car dont have a factory tacho.

Yeah, I figured I could do the 12V pullup coil to get a voltage spike for
the factory tacho. But since I have the 5V ECU tacho output inside the car,
I'll just stay with the Subaru igniter I have now. Saves making a new
igniter bracket, and messing with the underhood wiring.

Cheers... jondee86

[thegreatestben]

Just thinking about this more, does any one know if you can make a simpler version of the haltech/diode circuit that converts a link ecu tach output to a coil -ve triggered tachometer?

[jondee86]

Assuming the Link output to be a 5V square wave, I'm told you need this...



There have been a few threads about this on Toymods. Some people have
good success with this setup, and others none. The coil is usually the guts
from some small lights or horn relay found lying around at pick-it apart.

Cheers... jondee86