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I was actually trying to find a waveform for the ignitor tach output on the newer ignitors, or the older ones for that matter but can't seem to find them.
Guess it is sounding like there is a big enough difference between the IGF and tach wires then, odd that some piggybacks can use either but maybe they can accept a wider range of input for tach than the stock cluster.
Probably just need an adapter then, it should be able to pick rpm up from IGF like the piggybacks. I haven't used one before so can't recommend a specific one, but it would be similar to any used on the gte also.
probably could guess what the waveform looks like from standalones that are setup to ouput the tacho, might lead you to the adapter you need.
And for the pinouts, looks like there is only the tach pin on the supra ecu, the aristo seems to have it labeled as timing retard so would not give a tach output.
Maybe if you can find a supra ecu that might also do the trick.
All good not worth be getting the Supra ecu, I prefer the map sensor haha and I'll be going standalone at sometime in the near future.
Also ever since swapping in the AR5 I lost my speedo so I'm thinking of going with the Dakota digital adapter that can provide speedo and tach all in one.
Thanks for the replies only other way I have seen others make it work is by retaining the ignitor solely for the tach signal. I don't want a birds nest of wires or want to wire it in just for that purpose.
That and I guess maybe some people with a tt supra ecu get the great feature of the tach signal coming from the ecu itself.
Ok, after a ton of trial and error I still do not have a working tach .
I bought the Dakota digital sgi-100bt in hopes it would remedy my problem. I have come very close but still not 100%.
Good news is my tach does work. I can get the sgi-100bt to produce the correct signal to power the tach as it has a built in test option that sends a 2k rpm signal and my tach goes straight to 2k.
Bad news I cannot find a proper tach input to tap into.
I have tried the IGF, IGT, Injector.
IGF will not produce any signal through the adapter.
Injector will send rpm signal but between on and off gas it is erratic. Example when letting off the gas the tach falls flat.
IGT from coil 1 will send signal but it is erratic as well. Example when giving gas the tach falls flat and stays there unless the car is at idle.
Any ideas or anyone that has gone through this before?
After a lot of research and trial and error I found an individual online that has successfully done this on there 1jz. The individual was kind enough to pass the information onto me. So I will do the same here for everyone else to enjoy this mod with a working tach.
For anyone converting to smart coil on plugs. You willneed the following.
6x 1n4148 diodes
1x 2n3904 npn transistor
1x 3k Ohm resistor
1x 1k Ohm resistor
Follow the wiring diagram below
This is a simple and cheap method to resolve this issue. The Dakota digital sgi-100bt could not resolve this issue for me unfortunately. I made mine nice n tidy and put it right next to the ecu wrapped into the wiring loom.
If anyone is interested I can make more for a fee however they are pretty simple to make.
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