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Discussion Starter #1
Been looking around the forums for this fix, the Tach, what needs to be done exactly, is there a write up anywhere, anyone out there get their tach to work after completing the swap?
 

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All you have to do is get a tach from a Turbo. The 6spd will work on an auto, but you'll lose the P N D R etc. TRD tach will work also.
 

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The Great Kruso
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All you have to do is get a tach from a Turbo. The 6spd will work on an auto, but you'll lose the P N D R etc. TRD tach will work also.
+1, no other work around for it.

Kruso
 

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The Great Kruso
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There is a "work around" but it involves more than simply swapping out the NA Tach for a TT one.
I'm sure there's a way of doing it but none that has been identified on the boards. I have done one on a SC300 but when it came to the MKIV, I had to swap the tach altogether.
 

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Hardtopper
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I'm sure there's a way of doing it but none that has been identified on the boards.
It has been discussed many times. Search for Dakota Digital.

But like I said, it's far easier to swap out the tach to a TT as I have done so myself.
 

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There used to be a write up here. All you needed to do was to bridge two wires together and the stock N/A tach worked on the TT. I have tried to find that writeup but no luck. So I had to find a replacement tach for my friends swap.

On the other hand

I have a Auto TT Tach FS. LOL $50 Shipped.
 

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The Great Kruso
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I'll be damned, I must have searched for this for two days straight when I was doing mine. Stand corrected...

Kruso
 

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95 Supra under the knife.
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I dont mean to threadjack but Im doing this also. so what if you use a TT ecm, will the NA tahc work? if not what do I have to do to make the NA tach work? my car is a 6speed also.
 

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Former 1.5jz-Powered MKIV
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I dont mean to threadjack but Im doing this also. so what if you use a TT ecm, will the NA tahc work? if not what do I have to do to make the NA tach work? my car is a 6speed also.

The NA tach will not work with the TT ECM, you'll have a couple of options:

Replace the NA Tach w/ a TT Tach
MSD Tach adaptor 8920
Or Try the Mod above......
 

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The Great Kruso
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I dont mean to threadjack but Im doing this also. so what if you use a TT ecm, will the NA tahc work? if not what do I have to do to make the NA tach work? my car is a 6speed also.
?? This IS what they're talking about, how would that be hijacking the thread?

The NA tach will not work with the TT ECM, you'll have a couple of options:

Replace the NA Tach w/ a TT Tach
MSD Tach adaptor 8920
Or Try the Mod above......
Thats what I was under the impression of but Kirk is right. Here's the writeup copied and pasted from Clubna-t as posted by Captdale.

Take out the tach and look at the circuit board. See the 33K ? resistor on the top right hand corner. Jumper the resistor with a wire. Put it all back together. Hook up the wire from the TT Igniter A1 terminal (ext) to the blk/wht wire on the Diag connector (tach) and your good to go. Does not cost one dime and works just fine.

Apparently the NA tach takes a high level signal developed by the distributor/Igniter circuit. The TT ECU and Igniter put out a low level signal for the tach. The NA tach current limits its high level signal by putting a 33K ? resistor in series with the input. When you jump the resistor the tach is no longer current limited and the low level signal from either the TT ECU (A16) or the TT Igniter either one will drive the NA tach just fine.




 

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JZ motors in everything!
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Hook up the wire from the TT Igniter A1 terminal (ext) to the blk/wht wire on the Diag connector (tach) and your good to go"

From the ignitor that's terminal 4? Bottom right?

What is the wire on the "diag connector"?? I was thinking it means DIAGNOSTIC connector under the hood? There is no black and white wire there (97 harness)
 

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Hardtopper
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Where would you hook up the wire on a 97 tt harness ? Aristo ecu :(

Damn it.
I may be mistaken, but you do not need to do any wiring aside from jumping the resistor if you are running a TT ECU and Harness. The person who wrote the "tutorial" was running TT ECU on an NA harness and 2JZ-GE.
 

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JZ motors in everything!
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How does the 97+ harness get the tach signal if there is no wire?

thanks guys---

Im going to jump the tach and put the harness back to stock i guess.

So normal if someone uses a TT harness, aristo ecu and NA chassis they would just swap the tach out for a TT with no other mods to that area?
 
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