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Discussion Starter · #1 ·
Hey there, I've been building my dads 2003 tacoma with a 2rz.

My old man wanted a bit more powaaaaaaaaaa
I was gonna build the 2rz so he bought a spare tacoma with a 2rz.

I ended up getting a 92 aristo as a parts car and I was gonna sell the motor for a profit... my old man wanted the motor in his truck... so his wish is my command as his son lol.

We made custom mounts. cleaned up the head got it decked, arp headstuds, resealed the engine, built the auto trans (swapped from the 2rz manual to auto), single turbo, upgraded injectors, ecu etc.

I did all the wiring myself with a help of a few supra forum/facebook members, which I thank alot.

Only issues i'm having is the Tach is way off and the speedo doesnt seem to work at all.

hopefully I can get some help on this.

heres some pics and videos of the truck on instagram @secretsofspeed
http://instagr.am/p/CWBX4iVjNnz/ http://instagr.am/p/CS0zwL5AhrR/
 

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Mambeau / Admin
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... Only issues i'm having is the Tach is way off and the speedo doesnt seem to work at all.
hopefully I can get some help on this. ...
(1) Welcome to CT!

(2) About the Transmission and Speedometer

Hmmmmm ... According to Wikipedia a 1992 JDM Aristo 2JZ should have had an A340E 4-speed automatic tranny if it was a basic (not twin-turbo'd) 2JZ-GE. You made a reference to the twin turbo designation 2JZ-GTE, which was mated with a different variant of the A340E.

You need to verify once and for all which version of an A340E you have. For the reasons why and clues how to tell the difference see:


The 'E' means it was an electronically controlled transmission. The speed sensor signal from the transmission was electrically fed to the instrument cluster.

A 2003 5-lug Taco would have used an A44D auto tranny. I have no idea whether the speed signals from these two different automatics should or can be 'read' by your OEM cluster. The speedo reading is controlled by a control circuit within the cluster, not the speedo unit itself.

The gear ratios were different between the A44D and the A340E, and this will affect the speed signal and hence the speedo reading.

Bottom Line: I suspect you'll have to install a whatever-it's-called (speedo calibration unit?) and configure it to yield accurate speedo readings from whatever the A340E is signalling.
 

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Mambeau / Admin
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RE: The Tach

This Taco has a factory tach - right? If so ...

The OEM tach is unusable unless there's some sort of adapter / calibration module you can wire into the circuit from the source on the 2JZ end or ECM leading to the instrument cluster. The Taco's OEM tach circuit is configured for a 4-cylinder engine.

On a 2003 2RZ the rpm signal from the engine goes to the ECM, and the cluster gets an rpm signal from the ECM. However, the OEM tach reading seems to be controlled by the control circuit (chip, whatever) embedded in the cluster.

I'm not sure the OEM Taco cluster / tach will be compatible with whatever you're using for an ECM, so I'm not sure there's a workaround that would leave you with a working OEM cluster unless you can find and install a calibration / adapter unit to convert the signal.

If you're using the original 2JZ ECM from the Aristo, there might be some sort of signal or format mismatch that's driving the Taco's tach nuts. I have no idea how that can be overcome with OEM parts.
 

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Mambeau / Admin
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If that works to get you an accurate (or even just a realistic) tach reading, please post that fact back here. It would be a valuable clue to the mysterious internal workings of the 1995.5 - 2000 4-cylinder instrument clusters.
 

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Mambeau / Admin
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Here (attached) is the 2003 instrument cluster (with tach) wiring diagram. Both the water temp and oil pressure sender connections are shown on the first page. The IK2 connector through which both run is above your glove box behind the starboard / passenger side dash.

The water temp line is a yellow wire with a red stripe.
The oil pressure sender line is a green wire with a yellow stripe.
 

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Discussion Starter · #12 ·
Here (attached) is the 2003 instrument cluster (with tach) wiring diagram. Both the water temp and oil pressure sender connections are shown on the first page. The IK2 connector through which both run is above your glove box behind the starboard / passenger side dash.

The water temp line is a yellow wire with a red stripe.
The oil pressure sender line is a green wire with a yellow stripe.
Just hooked up my temp gauge lol, shows it maxxed right away lol
 

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Mambeau / Admin
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I found two green with yellow wires but one is on the smaller plug and one is on the larger plug
Do you mean the two OEM Tacoma connector 'plugs' that join at the IK2 connection? If so, that's that one would expect - two wires of identical color coding, one leading from the connection to the water temp sender and the other leading to the instrument cluster.
 

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Discussion Starter · #14 ·
Do you mean the two OEM Tacoma connector 'plugs' that join at the IK2 connection? If so, that's that one would expect - two wires of identical color coding, one leading from the connection to the water temp sender and the other leading to the instrument cluster.
I should of took a pic, the wires were kinda hard to see but there are two plugs one ontop of each other, one smaller plug and one larger plug. I grabbed the green wire with yellow stripe from the bigger plug. The smaller plug looked to be yellow stripe but it could of been light green. It was really hard to tell.

I'm thinking I might need to just put the temp gauge sender sensor from the 2rz on the 2jz motor to fix the gauge from pegging out.
 

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Mambeau / Admin
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... I'm thinking I might need to just put the temp gauge sender sensor from the 2rz on the 2jz motor to fix the gauge from pegging out.
If they use the same threading that could be a good test to try. If the sensor operates based on electrical resistance there's a good chance there's a resistance / ohm mismatch.

It's difficult to locate tech data on the resistance (etc.) specs. for such sensors and whatever they connect to.
 

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Discussion Starter · #16 ·
If they use the same threading that could be a good test to try. If the sensor operates based on electrical resistance there's a good chance there's a resistance / ohm mismatch.

It's difficult to locate tech data on the resistance (etc.) specs. for such sensors and whatever they connect to.
Is there a reverse wire from those plugs? I need to hook up the reverse wire from the transmission so it can turn the reverse lights on.
 

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Mambeau / Admin
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Clues, please ...

You never have confirmed whether or not the 'plugs' you're looking at are the IK2 connection.

If not, I have no idea what connection / connector(s) you're talking about ...
 

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Mambeau / Admin
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If it was behind the dash it would be the IK2 connector. Yes, the line leading back to the rear lights connects at pin #2 on the IK2.
 

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Mambeau / Admin
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The water temp gauge line should be connected at pin 10 on the IK2 connector.

The oil pressure sender line should be at pin 8.
 
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