Relays

[Big]

Am I correct in saying that to setup the 1UZ FE with original ecu,fuel pump ecu,hydrofan ecu that
1 Main EFI relay would run EFI+Fuel Pump+HydroFan all togther..?
2 Ignition relay runs starter motor and ignitors..?
I'm guessing I could setup each with there apropriate amped feed individually but is this necessary..?or just have enough feed amps to run them together as in the diagram..?(i'm just checking justto make sure i get this right.(i don't want to have every relay coming off just 1 or 2 feeds is all-that would mean i would have to have around a 100+amp feed to do so..right?fused of coarse..)

Ive been going over and over the SC diagrams and all it shows is these relays and feeds going to these relays..let alone of coarse the rest of the harness..

seeing as i now have the motor ecu+hydrofan ecu+ fuel pump ecu could this work..I just need to know how many amps to run to the apropriate relay.cheers

 

[gloverman]

Heres how we do it - Main EFI relay - switched by the ECU (ECU normally supplies a switched 12volt on toyotas) this relay supplies power to B1 and B2 on the ECU, the injectors and the IAC. A coil relay, a start relay, a fuel pump relay and a fan relay for electric fans. One important note is the coil relay is ignition switched and the main EFI relay is ECU switched. The coils need to be separate as the ECU resets the IAC ofter the key is turned off so if the EFI relay feeds the coils the engine will ran on for a little bit after the key is turned off.
As you have the cooling and fuel pump ecu these replace the fan relay and fuel pump relay we ran.
As for fuse size keep them as small as can do the job but some approxiate sizes I would use a 10amp for ECU /injectors. 15amp for fuel pump, hydro and coils but the hydro may require a bit more. We had another vehicle running a big single electric fan which would blow a 20amp fuse on startup and a VG30DET which would blow 15amp coil fuses on hard boost. If you want to get really techical then use your amp meter and measure the draw. We use a 100amp fuse on the alternator circuit and would use around a 40 or 50 on the power feed to the relays except the starter relay which would have it's own 50amp fuse. Remember if you do everything right the fuses will never be needed. Good luck with that - cheers

 

[Mrfuel]

Hi
This link was really useful just noticed you didn't talk about the circuit opening relay. How does it work and what is it association with the cold start injector if any.

 

[Big]

My understanding is the ecu takes care of the cold start injector..It's all in the way you setup the relays and who gets the first signal and then corresponding signals from there..best I can describe it..LOL:biggthumpup:
I'm sure sideshow or gloverman will help out..they're good at what they do..considering I'm a novice,i've managed to get it right after a few head scratchs..:zx11pissed:

 

[Mrfuel]

Hey thanks for the reply.

I bought an engine that doesn't have a fuse box or any of the relays. Would you be able to suggest a place in NZ that would do a new fusebox or a good auto electrical shop to get one from?

 

[gloverman]

I have access to plenty of different options. We generally use a 8 fuse holder and some aftermarket relay holders clipped together - Easy to do - cheers

 

[Big]

If you have a can do attitude then give it a go you'reself(Is the only way of learning..)...I just bought a fuse holder from repco and some generic relays(30 amp) and then just wired it up..:banana: :banana:

 

[Mrfuel]

Thanks

I have hopefully found some bits and piece from a donor car. Will see how that pans out. What should i grab from the car if i can? Fusebox, all the relays etc....