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2JZ VVTi fuel pump and other wiring questions

Guest |882|

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Guest |882|

I am currently designing my ECU pinouts and wiring loom for my 1998 Supra RZ VVTi using direct wire in. I didn't go plug and play because I'm far from having a stock TT VVTi! I have single turbo, using non-vvti IACV, Intake temp and also fuel pressure sensor through existing wiring that isn't used such as VSV's and AFM etc.

I've figured out most of the Inputs/Outputs and the IACV setup and I have based most of the pins from the V88-Supra loom using the V88 plug-in VVTi wiring PDF document to keep troubleshooting to a minimum and so I can use the base vvti map without too much configuration (Glen from ESP racing is going to send it through to me).

What I need confirmation on is with the Fuel pump wiring, ECU power hold, crank shaft trigger Ground and o2 sensors/wideband.

1) Fuel Pumps and removing fuel pump ECU

I am running 3x US denso intank pumps, they will each have their own relays and 12v+ fused battery power. I obviously want the V88 to control the pumps using 3x aux outputs as the triggers but also retain the safety that the stock fuel pump ECU provides (Like shutting down the fuel pump in case of an accident). In the main +14v supply diagram in the ViPEC manual the Fuel pump relay is switched from the +14v main EFI relay and is triggered by the AUX output (Ground). If for example the engine stopped does the ViPEC know this and shutdown the fuel pumps similar to the stock supra fuel pump ECU?


Can I use the +B wire that goes to the fuel pump ECU as the +14v switched power for all 3 fuel pump relays? Surely it sends enough amps over the one wire to trigger all 3 relays (it’s only a trigger not a load)? Then use the existing 2x wires to the fuel pump ECU as 2x of the AUX outputs and then just run 1x new wire for the 3rd pump to the V88. I've included a diagram below if what I mean.


2) ECU Power hold

Depending on the answer to the V88 safely shutting down the fuel pumps this might be already answered. If I follow the ECU power hold diagram using the stock supra EFI relay and ignition switch with diodes will this leave the fuel pumps powered on until the IACV is reset as the main EFI relay and V88 are still on or do the other AUX fuel pump outputs turn off?

Also are the 2JZ VVTi pins in the diagram correct? I’m assuming the plug and play kit has pre-wired diodes to the circuit board to provide this feature, I will have to manually add them.

Pretty much the goal for both of these question is keeping the fuel system safe with the ECU power hold function working using the stock supra wiring (apart from the fuel pump 12v+ wiring and extra AUX trigger wire to the V88).


3) Crank shaft trigger ground

Just confirming the Toyota crank shaft trigger goes to Ground (A25) not a sensor ground such as A24 or B22? VVTi wiring diagrams look to be using GND on stock ECU, just making sure!

4) o2 sensors

Can I use the stock o2 and Innovative LC-1 wideband together? Can I keep the stock supra o2 heater hooked up to an AUX output (Current INJ8) and the o2 sensor to Volt2 for CLL and then use the Output 2 from the LC-1 wideband controller to another volt input on the V88 for tuning?

I’m sorry if some things don’t make sense, I wrote this when it was late and I’m probably rambling :) Once I have all this confirmed and I can start the wiring, I might even post up or send you my custom pinout sheet to look over.

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Guest |882|

Think I'm pretty certain on the 3x pumps diagram using the same switched +14v from the b+ supra wire is fine but I'm still concerned about the fuel pumps shutting off and the other remaining questions.

Also for those interested I have 2JZGTE VVTi wiring diagrams and ECU pinouts located here, might come in handy for someone.

2JZGTE VVTi Pinouts - PDF http://www.2jzgarage.com/uploads/VVTi/Wiring/Supra_2JZGTE_VVTi_ECU_Pinouts.pdf

2JZGTE VVTi Pinouts - XLS http://www.2jzgarage.com/uploads/VVTi/Wiring/Supra_2JZGTE_VVTi_ECU_Pinouts.xls

2JZGTE VVTi Wiring Digrams (also includes non-vvti) - ZIP http://www.2jzgarage.com/uploads/VVTi/Wiring/vvti%20wiring%20diagrams.zip

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Use one Aux output to turn on all three relays. I would power the fuel pump relays direct from battery power. This is needed as you are using three pumps and not just one. The primary relay power must come form ignition switched power.

ECU hold power, is used to close the idle valve before the ECU shuts down. When you turn the ignition off everything including fuel pump turns off. Only the idle value is still active for a few seconds.

Trigger grounds in the Vipec harness are connected to A7, which is the shield ground. All grounds on the Vipec are common. You can use any of them.

Yes you can have the stock narrow band 02 sensor and the signal for the Innovate thing connected at the same time. Use separate volt inputs. Select one as narrow band and the other wideband.


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  • 3 weeks later...
Guest |882|

Thanks for the replies Ray.

I'm going to use 1 AUX for 1 pump - Fuel Pump output (Always running) and another AUX for the other 2 pumps - GP Output with 2x conditions setup (4000rpm and 10psi of boost pump 2 and 3 will engage)

The reason I have done this is because after some research and checking with people who have the same fuel pump setup they were having issues with running 2x or 3x pumps all the time. They heat the fuel and cause erratic AFR's after long highway driving or in hot weather. Another solution to this is to have a fuel cooler installed on the return fuel rail/hose, but most are just staging their fuel pumps for set RPM/boost levels as an alternative.

I've wired all the relays and fuel pumps up now and yes all the relays have their own fused power :)

Thanks for all the other info, makes sense just wanted to confirm.

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Guest |632|

Hey buddy..

as discussed i reccommend running all pumps at once as you are relying on the one way valves in the pumps to work correctly...

I have done a few wire in Vipecs in supras, Before ray released Pnp harness give me a buzz i'll help where i can..

Glen ESP Racing

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