New standalone, where to get power?

[D1andonlyantman]

Hi everyone. I'll try to keep this simple so bear with me. Basically im fitting a ecumasters EMU black to my VVTi TT6. Im making the harness adapter myself and have got most of the pins figured out but im wondering where to get constant 12v for the ecu, and ignition switched 12v for the ecu, fuel pump and VVTi solenoid? There are constant and switched 12v pins on the stock ecu harness connector but im not sure if they're up to powering all the above, specifically the walbro450 which is quite demanding from what i read? Would it be safer to run a constant straight from the battery to the ecu, splicing off of that wire and fitting a relay that is ignition activated? Then i can run the vvti, switched ecu feed and fuel pump off of that relay. The fuel pump ground will be on an aux pin on the ecu so the ecu has control.

 

Any easier options very welcome!

 

Hopefully that makes sense!

 

Thanks

Edited June 28, 2019 by D1andonlyantman (see edit history)

[Mike2JZ]

Located in the main fusebox you will find a relay called Main EFI. On a TT Supra there is Main EFI 1 & Main EFI 2. On an NA supra there is only Main EFI 1. EFI 2 is a dedicated relay for the fuel pump, wheras on NA supra the fuel pump ECU is fed from EFI1.

 

In the case of MainEFI1, on the stock wiring loom this will power your ECU, Sensors, IACV, VSV's, VVTI etc. Basically anything that needs a 12v switched source whilst engine is running. I recommend you reuse this system as it works fine, never had any reason to deviate to another power source for these items.

 

On a custom harness, you will need to wire the output of this relay to ECU & sensors that you require. Additionally, you will need to wire in a trigger to get this relay to activate whilst you have the key on ACC & START (Crank).

 

On the orange 36pin interior plug from engine harness, pin #13 is a ignition switched power that sends 12v whilst the key is in ACC & Crank. Connect this pin to the wire that used to go to ECU M-REL.

 

For the fuel pump, unless you plan to reuse the factory fuel pump ECU, you will want to run a ground switched (ECU activated) relay to switch power from the fusebox (EF1 or 2) to the fuel pump. If you look at the plug on your fuel pump ECU you will see a fat blue wire and a fat blue/red wire. The blue wire will be your 12v feed from the fusebox, blue/red will be your output wire from relay to fuel pump.

 

If you only have EFI1, and feel like you could do with another relay for dedicated fuel pump power supply, then you can add EFI2. There is some info on how you can do this to main fusebox here

 

Additionally, if you are doing a custom loom I would recomend you study this page. Wilbo666 2JZGE Engine Wiring. Even though this is the wiring for a 2JZGE, I would say 95% of the interior plug pins, and fusebox pins are very similar across TT, facelift etc, so will be useful to you if this is the first time you are doing a loom.

[D1andonlyantman]

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Edited June 29, 2019 by D1andonlyantman (see edit history)

[D1andonlyantman]

That's all great info, thanks a lot. Im not making my own loom really, rather making my own pnp adapter i suppose. The EMU black comes with a pinout saying what each pin needs (injector 3, coil 2, iat sensor etc etc) so i looked at the wilbo666 vvti gte pinout and found the relevant pins so i can wire the new ecu to a stock ecu header and use as much of the stock wiring as possible. As there will be lots stock pins left unused i wasn't sure what the knock-on effect of that would be, leaving circuits unpowered or ungrounded, so i thought it would be easier to make some dedicated circuits in places. Which does raise a fair point actually. Ive got the ecu paired up with the injector grounds but which circuit gives them their power? The EFI relay again i guess, so i will need to make sure that circuit is powered? this is the first time ive attempted anything like this so it is a learning curve as you can probably imagine.

 

Thanks

Edited June 29, 2019 by D1andonlyantman (see edit history)

[D1andonlyantman]

This is the pinout chart ive made. Not finished but most of the stuff is on there i think. Feel free to give any tips or pointers

 

Edited June 29, 2019 by D1andonlyantman (see edit history)

[Swampy442]

OK, I don't want to be 'that guy' but why dont you just get one of the more established ECUS, spend more to gain more instead of a wiring ball ache?

[D1andonlyantman]

Nah its cool. NO-ONE does vvti pnp. Not that i could find. I got some quotes on fitted standalones and it would have left me sod all to get the single turbo fitted. Plus despite this being a learning curve i do actually enjoy it. As long as i can get there in the end im happy to make the journey. Ive already spent some time learning some of the software, put hours into making that pinout chart and basically learning how it all works. The ecu basically controls the grounds to activate stuff. The 12v will always be connected (via ignition switch and relays etc) but its the grounds the ecu switches to control everything. Even learning something that simple suddenly made everything make so much more sense. If a sensor needs power it will be 5v (and 3 pin), if not and its 2 pin it just needs the analog input the ecu and a sensor ground, and the ecu will read the resistance. Once you learn a few bits it does make sense. With regards to the brand, ive known about this ecu for a while now. The software is intuitive and easy to figure out (with a great 'help' system), the ecu itself has plenty of safety features and general features - built in 4 bar MAP sensor, flex fuel, the lot. I have been speaking to people who use it and they're all for it. Plus its in a price range that sits well for me. That's why

Edited June 29, 2019 by D1andonlyantman (see edit history)