1JZ datalogging options?

destrux

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Is there any datalogging options out there for this engine that don't involve a standalone ECU or wiring up the whole car with $1000 worth of sensors and boxes?

I'm running a stock JZZ30 ECU with an AFC Neo for fuel control.

I'd just like to log RPM, throttle, boost, knock (or timing advance), and have an aux input for my wideband AFR.

I used to use a palm based datalogger on my DSM that plugged into the diagnostic port and did all that except for the AFR input. It cost less than $100 if I recall. Anything like that for this car?
 
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destrux

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lol. Not one of the thing I'd be willing to try to make.

So how do you tune these things with a piggyback without being able to look at the fuel trims and timing retard value?
 

destrux

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I would go standalone, but I can't afford it right now. If I go single turbo and upgrade my transmission I will, but for now I'm keeping the stock turbos and just looking to get a reliable 360hp out of them.

I haven't driven the car yet, so I guess it's possible it won't need much tuning at that level. I just want it to run right, not looking to tune to the edge for max power. This is the first turbo MAP based car I've ever owned though, everything else was MAF. It's still alot easier to tune, even at low power levels, when you can log the stuff and punch in the adjustments all at once then log it again.
 

IBoughtASupra

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Aphxero, do you know what readings will come up if you use a Snap-On scanner on the 1JZ stock ECU? It will be able to read it as long as you go to "Global" and use the different Toyota connector. Maybe it might show a few readings like the OBD1 Camrys do or is it just like the 7M and will only trigger the check engine to check for codes?
 

destrux

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I have an OTC Genysis scanner... I'll have to buy the OBDI toyota cable for it and see if it'll connect to the car. That would be sweet. I don't know how I didn't think of that before.... I use the damn thing everyday on other people's cars.

Probably have to use one of the other toyta or lexus models to connect though, for OBDI there is no global.
 

IBoughtASupra

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Maybe you can try a 94 TT Supra and see what you get, it would be nice because it would help with knowing how your engine since you are going to see what the computer is recording.
 

mkiiichip

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I think you implied you already have a wideband, but check out "Zeitronix". Its a dataloging wideband.
 

aphxero

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for piggyback i just tune wth a wbo2 by looking at it. and on most good dynos you can log afr. ive been using aem 1050 an 6050 on jz a lot. they are cheap and awesome
 

destrux

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I have a PLX wideband that logs to my laptop or to the shops dyno computer. When I'm on the dyno I can also log RPM and boost, but that only helps to tune WOT.

The main reason that I want to see what's going on inside the ECU is to see what the long term fuel trims are. It's best to tune the part throttle so that your fuel trims in the ECU are near zero (or near 100, whatever the "neutral" number is on this car).
 

te72

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I think you implied you already have a wideband, but check out "Zeitronix". Its a dataloging wideband.
Beat me to it. I have one of these, they're pretty nice. Not especially cheap though, I think I paid something like $350 for the whole setup?
 

destrux

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The OBDI cartridge and cable set for my scanner is only $200, but I wish I could find out if it read datastream or if it only did codes, cause I don't want to buy it and find out it's as useful as a paperclip.

I also found this on some toyota truck forum:

Toyota started implementing OBD-I in the '89 Cressida (7M-GE engine). I have found some info, but not enough to allow me to read data from my '93 Corolla. This is all I have (copy-paste from a Toyota PDF):

- There are three types of serial data: OBD, OBD-II and V-BoB (Vehicle Break Out Box). We're interested in OBD.
- Many Toyota vehicles with OBD, manufactured since 1989, have serial data stream available on the VF1 terminal of DLC1 (Check connector) or the ENG terminal of DLC2 (TDCL).
- Vehicles which support a serial data stream can be identified by the presence of a TE2 circuit. Depending on the vehicle, there can be as many as 20 different sensor, actuator and diagnostic data parameters represented on the OBD data stream. Accessing serial data on any of these vehicles is a simple matter using the Diagnostic Tester.

- The OBD Diagnostic Circuit:
This unidirectional data stream typically consists of 14 to 20 data words representing primarily sensor inputs and three outputs; injection pulse width, spark plug advance angle, and idle speed control command. Data is transmitted at a rate of 100 baud, updating on the Diagnostic Tester display approximately once every 1.25 seconds. Depending on application, the data is accessed from either DLC1 or DLC2. Data is triggered by grounding the TE2 circuit and reading the VF1 circuit.

I also found this website online that has a pinout of the 23pin DLC on this engine:
http://pinoutsguide.com/CarElectronics/Toyota_old_diagnostic_pinout.shtml
 

IBoughtASupra

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Buy, keep receipt and then return? :)

I would check my 1JZ but I am waiting on camshafts from Japan so I won't be running until hopefully, then ending of February or March....and that is on Express shipping from Japan, no Fast and Furious quotes intended.
 

destrux

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I found a cartridge and the toyota cable by themselves for $25 each now... but the cable has a round end. It looks like the round end might unplug to reveal a square plug behind the round one, some sort of dual-fit setup, but I can't tell. OTC's website says it fits these cars:

Lexus-Engine ’90–’93
Camry-Engine ’92–’94
Cressida-Engine ’89–’92
Lexus ’90–’93
MR2 ’85–’91
Cressida ’83–’92
Supra ’83–’91
Camry ’83–’94
Celica ’85–’91
Corolla ’85–’91
Starlet ’83–’84
Truck ’85–’91
4Runner ’91
Van ’90

Does anyone know if the stock diagnostics plug on any of these look the same as the 23pin one on the Soarer 1J harness? I'll check out my 87' 7M harness tomorrow, along with my mom's 94' Camry. I think I also have a 90' Corolla harness laying around.

I also found some interesting reading related to this, which explains my whole reasons for trying to read the fuel trims... for anyone who isn't sure what I'm talking about or why I'm bothering with this. This is an old toyota file I dug up on google....

http://www.autoshop101.com/forms/h48.pdf

Looking at this info... maybe I could build my own datalogger for this car. :naughty:

It even states that on models that have no serial datastream there's a voltage output that corresponds to the LTFT on the VF1 pin in the DLC.

That would be sweet.... you basically can tune your part throttle using nothing but a freaking volt meter as a gauge to see the LTFT in the ECU. That is.. if this ECU has no serial datastream of course... if it does you'd need a cable and a scan tool. If the ability is there though... chances are the OTC tool can read it.

From the info I found before, the absence of a pin in TE2 probably indicates that there's no serial datastream available.... which means it's as simple as using a volt meter to read the output of VF1. There's a note in one of the charts about TE1 being "off" while doing this. I'm assuming that TE1 is "off" by default, and that either grounding or putting power to TE1 would be turning it "on". It says that turning TE1 "on" and negating "IDL/CTP" (which I'm translating to "opening the throttle above idle/closed throttle position") would then cause VF1 to display an indication of whether the car is in closed loop or open loop mode.

This would make an awesome display gauge for the dash... one that displays fuel trim, and with the flip of a switch, also displays fuel system loop status.

I'm gonna check this all out tomorrow. I wonder what other stuff can be read from the DLC?
 
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IBoughtASupra

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Let me know so I can hook up my Snap On scanner when I get my car started to see what it is doing. Thanks.
 

te72

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Sounds to me like you're treading a path of your own here sir, and I support the idea. Can't really help you out unfortunately, but good luck and keep us in the loop!
 

destrux

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Yeah the second square plug looks like it might fit this engine, but I don't have a snap-on scanner. Mine is an OTC.

I'm probably going to skip the scanner route for now and see what I can do with a bunch of parts from radio shack and some time. I didn't get to test the volt meter fuel trim readout on my car today because of a family emergency (wife's grandmother passed away just after noon), but I will tomorrow.
 

mkiiichip

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You are correct in thinking the supra has no serial data. Dont bother purchasing scanner plugs for OBD1 Toyotas, ill explain.

I wonder what other stuff can be read from the DLC?
As you have already figured out VF is available from the diag block, there are only a few more signals available so dont get to excited.

IG- is RPM
FP is fuel pump signal voltage
OX1 is O2 voltage
TE1 is a check connector (for fault codes, check mode, etc)
+B is power
E1 is ground

As seen here. Called "Check connector" or (as i call it) Diag block.
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=48

These signals are all checkable with a voltmeter, thats why nobody uses a scanner for toyota OBD1 applications.

IDK if you have seen this before but this is a very detailed explination of what VF is. There is another good thread on how to use VF while tuning, I just cant find it right now.
http://www.supramania.com/forums/showthread.php?39856-Information-Vf
 
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destrux

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Thanks for the info, I figured at least a few people here had to have known about this.

I found another good article about it, the VF1 pin specifically...
http://alflash.com.ua/vf1.htm

Looks like the 1JZ, since it's a pressure sensor application, has only a 3 step output on VF1 for fuel trim. Still very useful, just aim for the fuel trim to be at 2.5v at warm idle and steady cruise. I checked my car at a warm idle after I reset the ECU and it was at 2.5V then moved to 0V after a few minutes.

I found a nice schematic online for a digital LED bar gauge that displays on a 0-5v range. I'm gonna build one and put it on the dash to display this full time, it'll make tuning easier and let me keep an eye out for problems even after the car is tuned.