2JZGE Na-T TT Ecu Mod
10-23-15, 10:41 AM
#2866
I finally figured out why my car was running mad rich and shutting off once it got to normal running temperature.
It was the crappy eBay injectors! I swapped them out for a set of Osidetiger 440cc and now it idles fine. Before this.. I sent out the ecu, tripled checked wiring, plugs, dis., map sensor, igniter.... This is huge for me.
Now I'm trying to set the timing but there is no audible change when I put in the jumper. Guess I should take a break and grab a beer.
It was the crappy eBay injectors! I swapped them out for a set of Osidetiger 440cc and now it idles fine. Before this.. I sent out the ecu, tripled checked wiring, plugs, dis., map sensor, igniter.... This is huge for me.
Now I'm trying to set the timing but there is no audible change when I put in the jumper. Guess I should take a break and grab a beer.
yeah the tps needs to be played around with to set timing, its not on "idl" right now.
Great news! TPS isn't set correctly if you aren't hearing the idle change when the jump is inserted.
So I was reading about swapping to an OBDII ecu and you have to wire in a ground for the heated O2 circuit. The reason they went to a heated O2 sensor was due to the fact that the non heated OBD1 sensors would sometimes loose their heat or cool off during times of long idling. This causes the tune to go off and richens the mixture. Once you drive off the exhaust heats the sensor and fixes the issue.
So I was thinking could adding a heated O2 sensor and add a ground make the tune more consistent? Is this a fairly simple upgrade, purchase O2 sensor, rewire it in, add ground?
So I was reading about swapping to an OBDII ecu and you have to wire in a ground for the heated O2 circuit. The reason they went to a heated O2 sensor was due to the fact that the non heated OBD1 sensors would sometimes loose their heat or cool off during times of long idling. This causes the tune to go off and richens the mixture. Once you drive off the exhaust heats the sensor and fixes the issue.
So I was thinking could adding a heated O2 sensor and add a ground make the tune more consistent? Is this a fairly simple upgrade, purchase O2 sensor, rewire it in, add ground?
if your car has a 1 wire o2 sensor, its worth upgrading at some point. if your car h as o2's with 3 or 4 wires, then you already have it.
the part number I run is a Denso 234-4209 and this is the "screw in" type for most downpipes, the one with the 2 bolt flange is a different part number.
you reuse the 1 signal wire for signal, you run a new pin to the ecu for the heated o2 which is basically the wire the ecu grounds to turn it on, then the other 2 are just normal chassis ground and a normal switched +12v power wire.
I haven't tried it but you may be also able to just ground the pin for the ecu heated o2 sensor, and then it will just be on all the time when the +12v is on. I have mine wired to the ecu but I think the ecu might have it on whenever the ecu is on so I am not sure the point of that, unless it turns it off sometimes, don't really know so I ran the extra wire. +12v and chassis ground you can find in engine bay, or run wires for those as well.
Some of the harnesses have the ground already some you may need to add it, I moved my grounds around so many times when I was figuring out if this mod will even work or not (way back when) so I couldn't tell you if I had it or not. it will be fairly obvious if its working though. the heated o2 sensor will start correcting within like 30-40 seconds of a cold start to 14.5, whereas the non heated takes many minutes to heat up and start correcting.
Denso 234-4209, you need just one of them. quite a nice upgrade for under $35 on amazon.
Last edited by Ali SC3; 10-23-15 at 10:45 AM.
10-23-15, 11:03 AM
#2867
Is there a heated DENSO O2 with the toyota 2 bolt flange? My downpipe is provisioned for the 2 bolt, not the thread in.
Is it a universal type ? Or is there connectors included generally?
10-23-15, 12:20 PM
#2868
Definitely change the o2 sensor out if you haven't before, no telling how old or lazy it has become over the years.
The gte ecu relies heavily on the map sensor, and on the o2 sensor. I would always install a fresh heated o2 when I am setting them up from the get go.
I have used the oem single wire one and it works alright but mine was also a new 1 wire one at the time. if the sensor is slow to react then you will likely be running rich quite often.
the only time you should see leaner than normal is on a hot start (engine fully warmed up and shut off and then restarted within 30 minutes), and it shouldn't be leaner than 16.x for very long, its normal.
If you see lean at any other time at idle then its not the o2 sensor its actually the safc or piggyback settings or too little injector. this ecu is set up to run a couple points richer and the o2 sensor to bring it back down. if the o2 sensor is lazy it doesn't lean it out as well and you get carbon buildup, waste gas, etc.. maf ecu's are set up to be more exact and dont rely as heavily on the o2 sensor to lean things out but they still work on the same principle of running a little rich in open loop and the o2 leans it out. if the o2 is adding fuel, then you will have issues like misfires etc..
these are universal type, just 4 wires with no connector but you wouldn't have the connector anyways unless you buy the other side from toyota or get it from a spare harness. The one with the connector is probably more expensive. you can also make a connector for it if needed I think I hardwired it because I was in a hurry. sometimes I use the GM weather pack connectors for these type of things since I bought the crimp tool a while back, like my distributor plug uses that so I can change to a 7m cps etc.. without any rewiring.
the universal 2 bolt 4-wire denso I believe is part number Denso 234-4206. a little more expensive but not too bad.
Don't use bosch sensors, our ecu's like denso.
So for others just take a look at the downpipe, if you see a flange with 2 bolt holes order the 234-4206, if you see one large threaded screw hole then order the 234-4209.
both of them are wired the same way.
The gte ecu relies heavily on the map sensor, and on the o2 sensor. I would always install a fresh heated o2 when I am setting them up from the get go.
I have used the oem single wire one and it works alright but mine was also a new 1 wire one at the time. if the sensor is slow to react then you will likely be running rich quite often.
the only time you should see leaner than normal is on a hot start (engine fully warmed up and shut off and then restarted within 30 minutes), and it shouldn't be leaner than 16.x for very long, its normal.
If you see lean at any other time at idle then its not the o2 sensor its actually the safc or piggyback settings or too little injector. this ecu is set up to run a couple points richer and the o2 sensor to bring it back down. if the o2 sensor is lazy it doesn't lean it out as well and you get carbon buildup, waste gas, etc.. maf ecu's are set up to be more exact and dont rely as heavily on the o2 sensor to lean things out but they still work on the same principle of running a little rich in open loop and the o2 leans it out. if the o2 is adding fuel, then you will have issues like misfires etc..
these are universal type, just 4 wires with no connector but you wouldn't have the connector anyways unless you buy the other side from toyota or get it from a spare harness. The one with the connector is probably more expensive. you can also make a connector for it if needed I think I hardwired it because I was in a hurry. sometimes I use the GM weather pack connectors for these type of things since I bought the crimp tool a while back, like my distributor plug uses that so I can change to a 7m cps etc.. without any rewiring.
the universal 2 bolt 4-wire denso I believe is part number Denso 234-4206. a little more expensive but not too bad.
Don't use bosch sensors, our ecu's like denso.
So for others just take a look at the downpipe, if you see a flange with 2 bolt holes order the 234-4206, if you see one large threaded screw hole then order the 234-4209.
both of them are wired the same way.
Last edited by Ali SC3; 10-23-15 at 12:32 PM.
10-23-15, 06:31 PM
#2869
you reuse the 1 signal wire for signal, you run a new pin to the eco for the heated o2 which is basically the wire the ecu grounds to turn it on, then the other 2 are just normal chassis ground and a normal switched +12v power wire.
I am a bit unclear on the "reuse the 1 signal wire" and "run a pin to the ECU part". I will likely be taking this to a shop who knows nothing of our mods to install. I want to be REALLY clear on what he is to do. Please give me the total nube version.
I haven't tried it but you may be also able to just ground the pin for the ecu heated o2 sensor, and then it will just be on all the time when the +12v is on. I have mine wired to the eco but I think the ecu might have it on whenever the ecu is on so I am not sure the point of that, unless it turns it off sometimes, don't really know so I ran the extra wire. +12v and chassis ground you can find in engine bay, or run wires for those as well.
If the other way is the sure shot, I'll try the method above.
Some of the harnesses have the ground already some you may need to add it, I moved my grounds around so many times when I was figuring out if this mod will even work or not (way back when) so I couldn't tell you if I had it or not. it will be fairly obvious if its working though. the heated o2 sensor will start correcting within like 30-40 seconds of a cold start to 14.5, whereas the non heated takes many minutes to heat up and start correcting.
I assume I won't need this part if I use the top method (if I am understanding this).
Dense 234-4209, you need just one of them. quite a nice upgrade for under $35 on amazon.
I got it for 29.99 on Amazon, Thanks!
I am a bit unclear on the "reuse the 1 signal wire" and "run a pin to the ECU part". I will likely be taking this to a shop who knows nothing of our mods to install. I want to be REALLY clear on what he is to do. Please give me the total nube version.
I haven't tried it but you may be also able to just ground the pin for the ecu heated o2 sensor, and then it will just be on all the time when the +12v is on. I have mine wired to the eco but I think the ecu might have it on whenever the ecu is on so I am not sure the point of that, unless it turns it off sometimes, don't really know so I ran the extra wire. +12v and chassis ground you can find in engine bay, or run wires for those as well.
If the other way is the sure shot, I'll try the method above.
Some of the harnesses have the ground already some you may need to add it, I moved my grounds around so many times when I was figuring out if this mod will even work or not (way back when) so I couldn't tell you if I had it or not. it will be fairly obvious if its working though. the heated o2 sensor will start correcting within like 30-40 seconds of a cold start to 14.5, whereas the non heated takes many minutes to heat up and start correcting.
I assume I won't need this part if I use the top method (if I am understanding this).
Dense 234-4209, you need just one of them. quite a nice upgrade for under $35 on amazon.
I got it for 29.99 on Amazon, Thanks!
10-23-15, 08:32 PM
#2870
Hey Ali, do you know which pin to use to add the wire for the switched ground? Is there an unused pin on the ecu that can serve this purpose on the JDM ecu?
"u reuse the 1 signal wire for signal, you run a new pin to the ecu for the heated o2 which is basically the wire the ecu grounds to turn it on, then the other 2 are just normal chassis ground and a normal switched +12v power wire"
So it's, switch over the one signal wire already there for the OBD1 1 wire non heated o2 , to the signal wire for the heated one.
Add a new pinned ground wire from the ecu to the heated o2 to switch it on when the ecu calls for it.
Take remaining two wires, one a chassis ground, and one a 12 volt+ wire and add ground to the chassis nearby and find a 12v + source . Any 12volt + source you recommend near that area?
"u reuse the 1 signal wire for signal, you run a new pin to the ecu for the heated o2 which is basically the wire the ecu grounds to turn it on, then the other 2 are just normal chassis ground and a normal switched +12v power wire"
So it's, switch over the one signal wire already there for the OBD1 1 wire non heated o2 , to the signal wire for the heated one.
Add a new pinned ground wire from the ecu to the heated o2 to switch it on when the ecu calls for it.
Take remaining two wires, one a chassis ground, and one a 12 volt+ wire and add ground to the chassis nearby and find a 12v + source . Any 12volt + source you recommend near that area?
10-24-15, 09:49 AM
#2872
So, happy to report that the new injectors and runner solved 100% of my problems at this point. All the weird idle and misfire issues are gone and the car feels and sounds much healthier.
Here is basically why these injectors didn't work properly. I'm guessing they will work properly with a vvti lower.
Also thanks to gerrb for selling me a crisp lower runner.
Here is basically why these injectors didn't work properly. I'm guessing they will work properly with a vvti lower.
Also thanks to gerrb for selling me a crisp lower runner.
10-26-15, 10:43 AM
#2877
187 glad it works, what injectors are those (left and right)? is that obd2 on left and is300 on right, still look a little different.\
glad the obd1 runner worked out, that is the best runner to run for the least issues. the obd2 one makes no sense to me anymore.
Studio, the 6spd ecu is the way to go, it responds better and has the higher rev limit, not much but noticeable.
also you can remove that a/c relay stuff and revert it back to stock a/c wide which is much cleaner setup.
ok let me see if I can simplify this a little bit (its hard for me my thoughts wander all over the place)
This picture is how it will end up looking, except this is a US ecu, for the JDM ecu the heater HT1 is actually pin B71, the USDM is shown in the pic and is B73. Use B71 if you run the JDM ecu, B73 if you run USDM.
So one of the stock o2 sensors (1 wire non heated) has a wire that comes from ecu pin B48, we call this the "signal wire". that is the only wire on the stock non-heated o2 sensor.
So the new heated 4 wire o2 sensor has a signal wire, a heater wire, a power wire, and a ground.
for the signal wire you reuse the stock signal wire going to B48.
For the heater wire, that goes to B71 on the JDM ecu (aristo and supra) (USDM ecu its B73 like in the pic shown)
For the power wire, switched +12v you should know what it looks like by now, you can find this in the engine bay or on the small 40 pin ecu connector (ecu A30/31) where you tapped power for your safc, bcc, map ecu, whatever...
For ground its just a chassis ground, find a suitable bolt that doesn't have paint underneath it and bolt the ground wire down, I think I use on of the bolts to the right of where the ecu sits for that stuff, you can also tap into one of the ecu grounds like your piggyback.
once you have those 4 wired up, the you are good to go. you should see the ecu home into 14.8 within a minute of startup, unless its like 40 degrees outside then it still takes a couple minutes cause of the extra fuel trim.
so to recap, reuse stock signal wire going to B48, add new wire going to B71 (for JDM ecu), add new wire going to +12v (black/red), and add new wire going to chassis ground (usually brown or just bolt to chassis).
I want to say I ran 3 new wires through the firewall so there wouldn't be wires running to a ground and power source in the engine bay, and you have to run the 1 wire to B71 anyways so whats 2 more.
(OPTIONAL METHOD), the other way to theoretically do it is to ground the wire going to b71 instead of taking it to ecu, but I haven't tried it so I dont know if it works. that would mean you dont have to run wires through the firewall but then wires will be running to power and ground in the bay which clutters things so I didn't even bother trying it.
glad the obd1 runner worked out, that is the best runner to run for the least issues. the obd2 one makes no sense to me anymore.
Studio, the 6spd ecu is the way to go, it responds better and has the higher rev limit, not much but noticeable.
also you can remove that a/c relay stuff and revert it back to stock a/c wide which is much cleaner setup.
ok let me see if I can simplify this a little bit (its hard for me my thoughts wander all over the place)
This picture is how it will end up looking, except this is a US ecu, for the JDM ecu the heater HT1 is actually pin B71, the USDM is shown in the pic and is B73. Use B71 if you run the JDM ecu, B73 if you run USDM.
So one of the stock o2 sensors (1 wire non heated) has a wire that comes from ecu pin B48, we call this the "signal wire". that is the only wire on the stock non-heated o2 sensor.
So the new heated 4 wire o2 sensor has a signal wire, a heater wire, a power wire, and a ground.
for the signal wire you reuse the stock signal wire going to B48.
For the heater wire, that goes to B71 on the JDM ecu (aristo and supra) (USDM ecu its B73 like in the pic shown)
For the power wire, switched +12v you should know what it looks like by now, you can find this in the engine bay or on the small 40 pin ecu connector (ecu A30/31) where you tapped power for your safc, bcc, map ecu, whatever...
For ground its just a chassis ground, find a suitable bolt that doesn't have paint underneath it and bolt the ground wire down, I think I use on of the bolts to the right of where the ecu sits for that stuff, you can also tap into one of the ecu grounds like your piggyback.
once you have those 4 wired up, the you are good to go. you should see the ecu home into 14.8 within a minute of startup, unless its like 40 degrees outside then it still takes a couple minutes cause of the extra fuel trim.
so to recap, reuse stock signal wire going to B48, add new wire going to B71 (for JDM ecu), add new wire going to +12v (black/red), and add new wire going to chassis ground (usually brown or just bolt to chassis).
I want to say I ran 3 new wires through the firewall so there wouldn't be wires running to a ground and power source in the engine bay, and you have to run the 1 wire to B71 anyways so whats 2 more.
(OPTIONAL METHOD), the other way to theoretically do it is to ground the wire going to b71 instead of taking it to ecu, but I haven't tried it so I dont know if it works. that would mean you dont have to run wires through the firewall but then wires will be running to power and ground in the bay which clutters things so I didn't even bother trying it.
Last edited by Ali SC3; 10-26-15 at 10:51 AM.
10-26-15, 01:14 PM
#2878
Yeah you got it, the dirty one is the stock injector and the is/gs style is on the right.
So far so good, the only thing I've noticed is a slight hesitation when very cold that goes away very quickly & a funky warm restart idle. It goes up and down 3-4 times then settles in. I'm assuming this is the IACV playing games. I'll be driving it a bit this week then tweaking on the weekend as usual.
So far so good, the only thing I've noticed is a slight hesitation when very cold that goes away very quickly & a funky warm restart idle. It goes up and down 3-4 times then settles in. I'm assuming this is the IACV playing games. I'll be driving it a bit this week then tweaking on the weekend as usual.
10-26-15, 01:41 PM
#2879
the slight hesitation when cold might be the tps position. if it goes away after the first time you press the throttle that could be it, I had it for a while then fiddling with the tps made it go away. not saying thats it only if it goes away after first press then check that out. it would hesitate the first press almost where the rpm's lower for a second, then second press it would act normally. I think its the ecu seeing the tps move and not the rpm's freaks it out then it adjusts on the fly.
10-27-15, 05:20 AM
#2880
187 glad it works, what injectors are those (left and right)? is that obd2 on left and is300 on right, still look a little different.\
glad the obd1 runner worked out, that is the best runner to run for the least issues. the obd2 one makes no sense to me anymore.
Studio, the 6spd ecu is the way to go, it responds better and has the higher rev limit, not much but noticeable.
also you can remove that a/c relay stuff and revert it back to stock a/c wide which is much cleaner setup.
ok let me see if I can simplify this a little bit (its hard for me my thoughts wander all over the place)
This picture is how it will end up looking, except this is a US ecu, for the JDM ecu the heater HT1 is actually pin B71, the USDM is shown in the pic and is B73. Use B71 if you run the JDM ecu, B73 if you run USDM.
So one of the stock o2 sensors (1 wire non heated) has a wire that comes from ecu pin B48, we call this the "signal wire". that is the only wire on the stock non-heated o2 sensor.
So the new heated 4 wire o2 sensor has a signal wire, a heater wire, a power wire, and a ground.
for the signal wire you reuse the stock signal wire going to B48.
For the heater wire, that goes to B71 on the JDM ecu (aristo and supra) (USDM ecu its B73 like in the pic shown)
For the power wire, switched +12v you should know what it looks like by now, you can find this in the engine bay or on the small 40 pin ecu connector (ecu A30/31) where you tapped power for your safc, bcc, map ecu, whatever...
For ground its just a chassis ground, find a suitable bolt that doesn't have paint underneath it and bolt the ground wire down, I think I use on of the bolts to the right of where the ecu sits for that stuff, you can also tap into one of the ecu grounds like your piggyback.
once you have those 4 wired up, the you are good to go. you should see the ecu home into 14.8 within a minute of startup, unless its like 40 degrees outside then it still takes a couple minutes cause of the extra fuel trim.
so to recap, reuse stock signal wire going to B48, add new wire going to B71 (for JDM ecu), add new wire going to +12v (black/red), and add new wire going to chassis ground (usually brown or just bolt to chassis).
I want to say I ran 3 new wires through the firewall so there wouldn't be wires running to a ground and power source in the engine bay, and you have to run the 1 wire to B71 anyways so whats 2 more.
(OPTIONAL METHOD), the other way to theoretically do it is to ground the wire going to b71 instead of taking it to ecu, but I haven't tried it so I dont know if it works. that would mean you dont have to run wires through the firewall but then wires will be running to power and ground in the bay which clutters things so I didn't even bother trying it.
glad the obd1 runner worked out, that is the best runner to run for the least issues. the obd2 one makes no sense to me anymore.
Studio, the 6spd ecu is the way to go, it responds better and has the higher rev limit, not much but noticeable.
also you can remove that a/c relay stuff and revert it back to stock a/c wide which is much cleaner setup.
ok let me see if I can simplify this a little bit (its hard for me my thoughts wander all over the place)
This picture is how it will end up looking, except this is a US ecu, for the JDM ecu the heater HT1 is actually pin B71, the USDM is shown in the pic and is B73. Use B71 if you run the JDM ecu, B73 if you run USDM.
So one of the stock o2 sensors (1 wire non heated) has a wire that comes from ecu pin B48, we call this the "signal wire". that is the only wire on the stock non-heated o2 sensor.
So the new heated 4 wire o2 sensor has a signal wire, a heater wire, a power wire, and a ground.
for the signal wire you reuse the stock signal wire going to B48.
For the heater wire, that goes to B71 on the JDM ecu (aristo and supra) (USDM ecu its B73 like in the pic shown)
For the power wire, switched +12v you should know what it looks like by now, you can find this in the engine bay or on the small 40 pin ecu connector (ecu A30/31) where you tapped power for your safc, bcc, map ecu, whatever...
For ground its just a chassis ground, find a suitable bolt that doesn't have paint underneath it and bolt the ground wire down, I think I use on of the bolts to the right of where the ecu sits for that stuff, you can also tap into one of the ecu grounds like your piggyback.
once you have those 4 wired up, the you are good to go. you should see the ecu home into 14.8 within a minute of startup, unless its like 40 degrees outside then it still takes a couple minutes cause of the extra fuel trim.
so to recap, reuse stock signal wire going to B48, add new wire going to B71 (for JDM ecu), add new wire going to +12v (black/red), and add new wire going to chassis ground (usually brown or just bolt to chassis).
I want to say I ran 3 new wires through the firewall so there wouldn't be wires running to a ground and power source in the engine bay, and you have to run the 1 wire to B71 anyways so whats 2 more.
(OPTIONAL METHOD), the other way to theoretically do it is to ground the wire going to b71 instead of taking it to ecu, but I haven't tried it so I dont know if it works. that would mean you dont have to run wires through the firewall but then wires will be running to power and ground in the bay which clutters things so I didn't even bother trying it.
Thank you so much. I will re-read this until I fully understand it. I may try to do this myself. I don't know any local mechanic I trust with "modding a mod" like this. They would probably have to read the TT ECU thread and understand those changes before moving on to the heated 02 installation. I really should start doing every thing I can on the modded areas of the car. Multiple people messing with the wiring could get confusing over time. I may just ask if I can work on my car a bit in my parking garage. You are actually not supposed to.
Thanks again guys!
