oh my! rb26 injector resistor help!

[drftnrps13]

ok i didnt have a resistor box with my harness so the company that did my wiring just wired resistors in them self. but know i try to start my car and no fuel. the signal is there but the injects wont fire. i supplied my own 12 volt and ground to the inject and it fires. this rules out stuck injectors. so know what! i cant find the resistors the company said the wired in, so what do i check? I thinking the resistors that got wired in are wrong, or they wired something wrong and the ground signal is too weak to fire the injector, why it doesnt fire when i crank the engine. help anyone!!!!

[StricNyne]

someone is selling a accord v6 one which will work

[DriftingisLame]

visually inspect the resistors they wired in, and then check resistance past them. They should be no more than 10 ohms, and if they are excessively higher, or no continuity, the injector will not fire.

Put the key in the on position, remove the CAS, and manually turn it. Listen for the injectors to click, or touch them and make sure you can feel them click.

How do you know its a fuel issue? One really fast easy way to tell is to shoot carb cleaner down the intake while cranking, if the car tries to start, its fuel, if its the same problem, its probably spark.

I've had crank no starts before due to something as simple as the ground pin on my ignitor backing out of the plug.

[drftnrps13]

i know its a fuel issue, i did the starting fluid and the car runs off of it, so i know its fuel. thats a great idea with the cam angle sensor. ill try that tommorow. but see the problem with the resistor test is i dont know where the company wired the resistors.!!! where is a comon spot to where they install them? but is there any other way i can check the resisance, like from the ecu to the injector? more info please.

[Coolwhip]

Break open that harness to find where they are. They shouldn't be too far upstream the harness from the injector plugs themselves.

[drftnrps13]

i check from the injectors to the area where the coil pack harness plugs into and no resistors!! how much futher?? does the resistor placement have an effect on the type of resistor needed? but ill keep searching! im gonna take the whole harness out tonight and open it up to find where they are. the company that did my harness removed the stock resiston plug so they had to have wired in the new resistors!! ill post again tomorrow with a new update. and more info would be great!

[Coolwhip]

you're in Florida as well, what part? And I would contact the place that did your harness and get confirmation on where those are at.

[craz4240]

The resistors should be somewhere between the injector harness and the ecu,you may have to peel back some of the sheathing to trace the wires back.

[gawdzilla]

the company that did your wiring is probably bs'ing you about the resistors being there. my guess is they're not. the resistor pack or individual resistors won't be so small that you can just hide them in the harness loom. in the oem setup, the resistors are on the + side of the injector. between the injector and the ecu is the ground side. the resistors shouldn't be there.

thats about all i can help without seeing your harness...

[WhatsADSM]

You just want to know if they wired in resistors or not?

Thats easy. Unplug an injector. There should be 2 wires, one is the "hot" (i.e. 12v powered) wire and one is the "signal" wire. So first check with a multimeter in DC Volts mode looking for the 12v wire. You will likely need the ECU in and the car in the "on" position without it running.

You should find one of the wires with 12v on it. Now ignore this wire, because we want to check the signal wire. So now unhook the ECU, turn off the car and remove the multimeter. Now set the multimeter in resistance mode (Ohms). Now check from the signal wire at the injector plug to the pin on the ECU that fires that injector (look this up in a ECU pinout). This will tell you very quickly if they put in the resistors like they should have. The resistance should be somewhere around 10 ohms or so. If it reads almost 0 that means they didn't wire in any resistors.

[WhatsADSM]

O and BTW... they can put the resistors anywhere from the ECU to the injector and functionally it is the same.

[gawdzilla]

^no. the resistors are supposed to go on the 12v side, not the ecu ground side. theoretically you can put it on either side, but from the factory it is on the 12v side

[skylinegrl13]

i've been looking, who is selling??

[WhatsADSM]

good call. It can be wired on either side of the injector the electrical model is the same... makes no difference.

So you still use the same thing I outlined however you will want to check the 12v side for a resistor as well. So this means once you have identified the 12v wire. You will test for resistance from the 12v pin at the injector to the 12v feed...

I believe the feed was from a relay or something, but it has been a while since I have had my RB.... Gawdzilla, where does the 12v feed come from?

[gawdzilla]

Gawdzilla, where does the 12v feed come from?

r32 FSM shows it coming from an always hot 12v source, not from ign, acc. then again that can change since it is a swapped car

[Darius]

So since there is one common 12V power wire to the RB25 injector harness, could one resistor be used or does one have to be installed for each injector?

[gawdzilla]

So since there is one common 12V power wire to the RB25 injector harness, could one resistor be used or does one have to be installed for each injector?

pretty sure you need separate resistors, and there must be a reason the factory is like that (not to mention all other factory cars with resistor packs). maybe heat dissipation, i dont know.

[WhatsADSM]

pretty sure you need separate resistors, and there must be a reason the factory is like that (not to mention all other factory cars with resistor packs). maybe heat dissipation, i dont know.

Needs to be one resistor per injector a little for heat/reliability but more importantly so that each channel receives the same current during the fuel injection pulse. Otherwise if you have some overlap in phasing between 2 injector drivers on the same 12v feed then the current would be too low during the overlap period.

So to the thread poster you will want to measure both sides (starting with the 12v side) of the wiring harness at the fuel injector to ensure that you find a ~10ohm resistor in series with each injector.

[drftnrps13]

ok thanks for all ur help, i solved the problem. the resistors are there just the guy who did the wiring used a 12volt source that like 10 iother things were running off of. so i know but the resistors 12volt source running off it own source, and now it works!! thaks all

[gawdzilla]

Needs to be one resistor per injector a little for heat/reliability but more importantly so that each channel receives the same current during the fuel injection pulse. Otherwise if you have some overlap in phasing between 2 injector drivers on the same 12v feed then the current would be too low during the overlap period.

good point