So I completed the NAT mod on my manual transmission 95 SC300 in the fall of 2019. (https://www.clublexus.com/forums/bui...w58-build.html)
The mod went well and I have been driving it for a few years with no problem.
For the NAT mod I used an ECU from a 95 manual transmission Supra part number 89661-14501.
I am considering replacing the ECU from the 95 Supra with an aftermarket ECU (Likely and EMU Black) so I am not limited by the Supra ECU to 14 psi.
My question is, when I start with a base map, would I use the one for a 95 manual Supra? I am thinking I would, but I just wanted to make sure I was not missing something.

The ignition in my SC is a distributor.

Thanks in advance for the help.

Bruce

 

Depending on how much more boost you want to run you could add some piggybacks to the stock ecu that could also work.
You would want to start with a map that is for a 2jzge na-t specifically since you are still on the distributor, and avoid the ones for a 2jzgte.
There are probably lots of members who run one of those maybe post up a thread or see if there is an EMU black thread already.

 

Ali, thanks for getting back. I will do that.

 

Hey guys I know this thread is quite old but im having issues with the tt ecu mod. I have green giant 440s, tt map senosr, tt ecu, iat. Walbro 450 12v mod. The car will start but then slowly die (will die after 4-5 seconds) , and for some reason when im setting timing, the light wont flash repeatedly (maybe once every 2-3 seconds). CEL is on for code 27 31 35 47 78(maybe bc of the 12v mod). But like i said i cant even set the timing cuz the timing light wont flash repeatedly. PLEASE HELP.

 

With the code 31 you probably have an issue with the map sensor wiring or a bad map sensor, that ecu sees the map sensor is at a higher voltage when it isn't working and it dumps fuel and the ignition will wash out sometimes.
start with code 31, check the wiring and test the sensor, lots of them have gone bad you would not be the first.

 

Hey Ali thanks for the reply, anyway so I got codes 27 31 and 47, everything else cleared. I was able to get the car started but now it won't even start :/ I believe the map sensor is bad bc the wiring is good, I'm getting around 5v at the power, same for the signal (62b) and ground is teed with iat that seems to be working fine (Ign On). I asked around and I heard that the map sensor I'm using (89421-12111) Is a vvtii map sensor and I need a nonvvti map sensor since my eco is non vvti. Can you confirm? Do you have a part number for that map sensor? Also the tps I'm using is from a 7mgte that came with the ffim I purchased, I saw somewhere that 7mgte and 2jzgte tps are cross compatible. Can you confirm this? Thank you again

jzKing

 

The 2JZ map sensors are the same. if you are seeing 5v on the signal something is wrong. should be 2 something with the car off and 1 something with the car on. It probably bad or fried. when the ecu sees 5v it thinks its wot and won't idle or stay running usually if you can get it to start.

2jzgte map sensor turns the opposite way of the 2jzge one and the 4 wires in the connector are flipped because of that.
So if you have a GE harness and a gte type tps, you have to flip the wires. ge harness and ge tps you don't need to flip.
7Mgte not really sure which way it rotates, but if it rotates like a gte or was meant to originally replace a gte sensor then you probably need to flip the wires in the ge harness.
This could be part of your wiring issue as the tps uses the 5v and sensor ground wires.

 

My car is an import soarer with the 1jz style plug and I'm using a 1jz GTE ecu.
so ive wired mine up using wilbo 666 wiring diagram and oulled the igniter into the footwell and wired vvti coils from there.

Fairly confident on my wiring as im an elec engineer by trade... however.
It won't fire.

It will crank but I have fuel pump ecu supply but no control signal from the ECU. (pins are different for the 1jz ecu but I expected 5v and have 0v)

Similarly I have no ignition....

Now when initially connecting a new battery as I don't leave it on the vehicle. the relays will click on and off a lot and the injectors pulse for a while as do the coils fire. I assume this is normal.

does anyone have an idea what could be holding it off?
I.e. cam sensor inout (still using the dizzy base)

Or would it not try and crank.

My next move is to link out the fuel pump ecu to temporarily remedy this but i feel its something the ecu is looking for that is stopping fuel or spark outputs.

Kind regards.

 

I am guessing you want from 1jzgte to a 2jzge na-t, if that is wrong then let me know.
Did you rewire the 1jzgte harness to the 2jzge engine? that is my guess from what you said.

The 1jzgte uses batch fire injection and high impedance injectors, the 2jzge uses sequential injection and high impedance.
So you can reuse the 2jzge type high impedance injectors but if using the 1jz ecu you must use the 1jz harness to keep the batch fire happy.
If you are using a 2jzge harness and rewiring, you should not be using the 1jzgte ecu and upgrade to the 2jzgte ecu at this point.

Next the ignition, you went from the 6 channel to the 3 channel which is fine as long as you get the wiring right, make sure the right cylinders are paired and the orders.
Not going to go through all of it but everyone makes mistakes, even an electrical engineer because the wiring is complicated the first few times for everybody, I have made a few myself over the years.

When you rewired the 2jzgte harness to the 2jzge distributor, you have to make sure you get a few things correctly.
The GTE has 1 crank and 2 cam sensors, each have a signal and a ground. On the 2jzge, all 3 of those grounds go to the ground on the distributor (shared ground for crank and cam).
The other thing that you also need to make sure is you have the polarity correct when you move the crank sensor wiring over, mixing up the signal and ground wire will give the wrong/weak signal and it wont start or will act like its trying to start but never seems to actually run and hold an idle. So check the polarity make sure the right wires are going to ground, this happens since you have to rewire those unless you use the newer oil pump with the crank sensor on the oil pump, then you can use the distributor for just cam signals. This would be my first place to check, second would be the ignitor wiring.

I want to say the SC and Soarer fuel control is usually a pulsewidth modulated signal so you may not see a solid voltage on it especially when its ecu is signaling low voltage mode vs high voltage mode.
If you were to scope the output signal from the ecu you would see it come up, but seeing as the 1jzgte ecu was already in your car im guessing, this shouldn't have been affected by your rewiring.
Later years and other models they went back to a regular on and off voltage and low mode was handled via a fuel pump resistor usually in the engine bay.
You can temporarily turn on the fuel pump by jumping FP and b+ on the diagnostic connector though, you should hear the fuel in the rail recirculating when you do that even with engine off.

The clicking of injectors and coils is not normal if the key is in the off position. I would also throw in the possibility of a bad 1jzgte ecu. At this day and age there are more not working ones than working ones, so unless it was in your car working before I wouldn't even personally bother with making a 1jzgte ecu work in anything cause likely it wont last you that much longer age wise without a rebuild and then they are iffy as well.

I would have advised from the start to get a 2jzgte ecu or standalone and rewire the body plug to your soarer. you will pick up power and drive ability just from going to sequential injection.
The 2jzgte ecu's are pretty old now even, so if you can find a good one and keep it in good shape it could last a while still, but many are just going standalone these days cause alot of these ecu's do need a rebuild or will need one in the near future. Remember I wrote this thread 13 years ago, so all of these ecu's are that much older. 1J ecus were old and iffy back then, I honestly wouldn't even consider running one unless the ecu is original to that car and still in good shape like yours maybe is. good luck if you have more info or did something post it up. My 1jz knowledge is more limited but I know a few things about them.

 

So I've managed to get the fuel pump running.

It now runs when cranking at 12v, and then runs over for about 3s after I stop cranking at around 15v.

so I'm happy with that end...

still have no spark, and no injectors when cranking though.

I should add, I've also gone to ffim, with a gte TPS, and flipped the wires.

For information the ecu is an automatic ecu, I removed the Neutral pos link and no crank at all.

checked grounds and ran extra ones....

bad ecu? Bad igniter? Bad wiring 🤣

short of pulling the loom and belling it out, does anyone have any classic places to start/look at?

thanks

 

Apologies, I think I was typing my update as you submitted your reply...

I'll have a look at the things you mentioned. Sincerely appreciate your input.

The ecu did come from a running car, I have taken the 2jz soarer loom that came in my car and wired it to suit the 1jz ecu using the wiring diagrams in this thread and wilbo 666 wiring disgram, the engine itself ran fine in the car before this so i can only assume a wiring issue by me.

Again I'm only using a 1jz ecu because my harness came with that connector type, I did originally have a 2jz ecu for it. And opted to try this way.... mainly for the challenge. Could be my undoing!

 

I thought you went from a 1jzgte to a 2jzge na-t with the old 1jzgte ecu and harness, but it sounds like you had a 2jzge engine and harness in your soarer originally.
does the soarer 2jzge harness have a 1jz plug on it or did you rewire it to the older plug?

Usually people have a jumper harness to go from a 1jz harness to a 2jz ecu. you could use something like that or get a custom harness made, or you could rewire your plug and add the missing injection and other wires to a 2jz plug.
I would say grab a non vvti sc300 harness and start from that because it will have the right body plug and the right ecu connector for a non vvti 2jzgte ecu, but it would be for LHD and assuming yours is a RHD.

Using the import 2jzge harness if it has the 1j plug should work theoretically with the 1jz gte if it is wired right, so you will need to make sure all the injection wiring matches (im assuming that version both are batch fire) and the rest of the ignition stuff also. Make sure IGF is connected or the engine wont stay running.

 

Yes that's correct. Factory RHD 2j soarer chassis and loom. With a modified 2jz harness to accommodate the igniter and vvti coils. My car and harness is an early soarer so it has the 1jz style plug.

I haven't altered the wiring for the injectors so I presume that it was batch previously (I will check) but again none of them are firing, if they were wired in 6 you'd expect just 3 to fire, as the ecu only has 3 outputs for injectors.

The odd part is I have no spark either, so thats what lead me to think crank / dizzy that would inhibit both. Do both engines use the same sensors / signal types etc? I realise this may not be your area of speciality so thanks for your input so far.

Ill will check the igniter wiring for the coils and check the batch fire for injectors.
i just cant think of what would inhibit both.

Something else I may have overlooked?

I feel like it can be done, and I can't find anywhere that it's been done before so I'd really like to persevere with this route for now, abs then upload it for others for future too.

I think by the time I've purchased a used harness and ecu which may or may not be functional it probably isn't far off the cost of a standalone, but I am aware this mod is old now and ecus are dying, particularly the 1jz ecu's.

Thanks.

 

I think you should be able to get it to work then and makes sense since that was all in your vehicle already. I would try and get the 1jz ecu to work first, it probably is something simple.

The cam and crank input being incorrect would stop most everything so it could be that.
I would be suspicious of the cam and crank wiring then, on the 2jzgte ecu the ground for those is connected internally in the ecu so you can leave the shared ground of the 2jzge distributor alone.
Purely a guess but maybe the 1jz cam and crank grounds are not internally connected (you can touch both pins on ecu and do a continuity check), so if they are not connected you may have to run a 3 separate wires from the distributor shared ground to the 3 ground wires for the cam and crank and the ecu. Hopefully once you look at the pinout diagrams again that will make sense.
Also note the cam and crank wires have a grounded shielding on them, keep the signal wire insulated from the shielding if you do any wiring.
The cam and crank ground is its own special ground, there is also a separate 5v sensor ground typically for tps map sensor etc.. and then there is the standard chassis ground for everything else usually 12V. None of these should be mixed up when rewiring.

I would assume alot of the other wiring is the same since they both had the same ecu plugs. You may want to 12v mod the fuel pump just to be sure its staying on.
I am assuming you also swapped out to a 1jz map sensor, should be able to reuse the IAT.

Verify that the ignitor has 12V with the key on and the injectors have 12V as well. If not it could be a difference in how the ecu turns on the EFI relay(s).
On the US 2jzge there is just one EFi circuit but on the US 2jzgte there are 2 circuits. It usually doesn't make a difference as they all normally turn on with the same signal from the ecu but thought I would mention it as this happens with key on so if you don't have 12V then its a power issue before the distributor.

Another one to note is the noise filter for the ignition system, the little grey plug in the bay with 2 wires going to it. when you swap ignitors you need to leave that grey plug in there as it removes noise on the cam/crank power line.
Some people take it out or disconnect it and have issues. another common one is the cylinder head to firewall ground, you need that or the ignition will go haywire.

If you weren't sure about any of the wiring you did, post it up. not all the functions will match up but the main ones are usually left in the same place.
Toyota has been known to swap the location of IGF though to prevent swapping ecu's that have the same plug, usually for different years or chassis or engine combos, or even randomly.
I would check that they didn't flip the location of the ignition pins 1-6 and IGF to prevent swapping in a 1jz ecu exactly like you did. They do this on at least the 2uz ecu's of different models/years.
With no IGF the engine should start and run for 1-3 seconds and then cut out. should also throw a CEL code. Also are you getting any codes?

 

Thanks again Sir for your in depth reply, I'll check out those options thanks.

I had wondered if there was a difference in the output signal from the dizzy to 1jz or 2jz cams but they both use 12 per rotation per cam which is the equivalent of the 24 pulses per revolution from the distributor. So hopefully that rules that out.
I will check the independent grounds definitely as aside from the MAP sensor 5v driver I assumed that ground meant ground and I have grouped some of them together.

I'll let you know of any updates / developments!