Can s4 fuel inj resistor be used in s5?
 

I did a s5 motor swap into an s4. Everything is going fine, but when installing my haltech ecu, trying to wire my hi imp fuel injectors, I'm running into a problem. I still have the s4 inj resistor. Do I even need it anymore with the haltech and wire the injectors from the main relay to provide 12v, or do I need to order the s5 resistor relay?

just disconnect the resistor. its underneath the stock air box. i have an s5 motor but im still running low impedence injectors.

The injector box is for low impedance injectors thus does not need to be used w/high impedance injectors, but if you do not use the injector box when running low impedance injectors then it is just a matter of time before the injector driver(s) within the ECU will burn out.

I took my Haltech and ran 12v from the Ignition switch.,
The Haltech should run the injection system and have the capability within the software to adjust for the injector impedance.
What Haltech do you have?

*(by the way,IF you would have followed the Rules of posting and gained posts you could have accessed the Haltech section to get answers for this..Just a kind reminder that they may be rules BUT they do really help you!)

I've got the Sprint re platinum ecu. Its on an s5 engine swapped into a s4 car. Using hi impedance injectors. So I just need a 12v supply to the injectors? No relay?

You should have a Wiring diagram for that with your ECU.
If not go to the Haltech website and it should be readily available there.
My PS1000 was a snap to wire up.
12 v to ignition,wire to pump..Tps,Cas,coils,Injectors,etc were all on a Premade harness made by the "Famous" Chris Ludwig!..heh! (LMS-EFI.com)

some good info for ya.

http://www.haltech.com/wp-content/up...ing_rev_a-.pdf

http://store.haltech.com/usastore/un...istor-usa.html

Now,I will post this,just as an opinion.NOT 100% on this,it is an observation.

It looks like IF you LOW imp injectors then you just wire them up.
that Fancy 150 dollar resistor pack is exactly the same rating as the S4 resistor pack SO if you run the HIGH's then it looks like it could be wired in to the harness.(saving you about 145 bucks..lol!)

Thanks for the info. The confusion that I'm running into is that when I looked up fuel injector relay, it shows 2 different ones. One from the s4 and another for the s5. In the haltech diagram it show how to wire each injector for signal ground, just not the 12v constant. Didn't know if I should wire it from the main relay (or another 12v constant) or through the resistor relay.

Your car wiring would not really be used and the Haltech will now basically control the engine functions.

That means once the ECU gets power then it should by rights control all other things attached to it.So scratch anything operating on the driver's side sort of thing,But leave the engine bay fuse block etc as some other crap runs through it
Now if you decide to put on aftermarket coils then you can use a relay and get the Haltech to kick it on.
The injector wiring shows 4 wire going to the injectors and names the locations.The "other wire" of each injector is ground.That means that the Haltech is supporting the injectors.They do not need a relay.
The fuel pump is easy.Use the stock wiring as normal but get the haltech to deliver 12v to the pump.(actually I think that there could be a relay involved.).
That way the sender gets its reading like normal but the car'sold wiring no longer operates the Pump.

This info is just from what I have gained as I had went and swapped a S5 TII into my S4 N/A chassis..so it's all I know,as I understood it.
You should be gaining posts to Jump into the HALTECH section as this is a little above the average NEW Joe's head.

You've been super helpful. I'll be wiring the injectors to 12v source without the relay. The fuel pump DID require a relay. Located it under the steering column. Hopefully I spliced into the right wire.

ya,my harness was a little more complex and the guy that made it (lms-efi.com) Chris Ludwig is a master at this stuff and also a Vendor that frequents the Haltech section.
The harness made it super easy to install and all the Relays were already wired and just needed power.
Now I took a couple years electronics back in High school...(wah?...when dinosaurs were pets!) but I was sort of torn with how my connections would be and if I could properly wire it.
So instead of second guessing I had Chris make it up and BOY!,I did myself a big favor and saved alot of headache!

Hindsight being 20/20 lol. It really wasn't that bad though. Just kind of ambiguous in the instructions as to what connects to what

I've been slapped for hindsight..lol..
(quit starin at my Hiney...!)