jzs14

Ok, correct me if am wrong but I thought this is how it works. Stock injectors are high impedance (they have high resistance). My stock injectors and the 440's have 13 ohms resistance. Now when you put a resistor pack on you need it because the 550's are low impedance. They have low resistance (lets say around 4ohms). So with low resistance you are sending a lot more current through the wires. Therefore if you put on 550's with no resistors they will fry your ecu injector drivers. So the point of a resistor box is to bring the resistance with the 550's back to the normal 13ohms your ecu is always used to seeing. I was getting only about 8ohms at each injector so maybe there was still not enough resistance and too much voltage going to my ecu. Am I right or did I totally just write some bs.

Ali SC3

iTrader: (10)

your thinking is correct for sequential ignition, where each driver fires one injector, but you are considering the resistance for each injector individually on an ecu that fires 2 injectors together so it gets tricky.

the 1jz fires 2 at a time, so from the perspective of the injector driver, you have 2 parallel paths 1 to each of 2 injectors, and when the resistance is equal on 2 parallel paths it divides the total resistance by 2 as seen by the driver.

So what happens is that each injector individually may be in the acceptable range of impedance, but when firing 2 together depending on if they are on the high or low side of that range individually, will impact what value is after the division of the 2, and it you are on the way lower side, you wont have enough resistance to satisfy the injector driver and hence frying it/shorting it out very quickly.

Not saying this is what happened, but thats another explanation of what stock hatch was saying.
While the TT esistor box is known to work on both sequential and batch fire, it is not known if the same is true for the acura box. if the resistance is identical to the TT, then it should make no difference after division. If it is a few ohms off on each individual resistor path (for example 8 instead of 13 lets say), it will create a difference when you do the parralell division on them when used in batch fire mode, mainly the acura would give you 4 and the TT would give you 6.5 ohms. If that difference will fry the circuit not really sure but that may be a part of whats going on and why the acura box works on the sequential but maybe fried your drivers in batch. hope that makes a bit more sense.

so either you fried the injector drivers, or something completely unlrelated is going on that is causing your issue.
on the 1jz ecu I would just simplify and install a 7m resistor pack. It is designed for batch fire.
or if you feel up for some work you can even go to a 2jz ecu now and rewire it all, but thats alot of work.

tonysc400

so you guys are thinking that the acura resistor box is whats causing this?

what is the outcome on this situation OP?

fried_rice

iTrader: (20)

EDIT: Had a bad multimeter
I purchased an Acura Legend resistor box before reading all this info. It reads 6.1 ohms. My MKIV injectors read 2.2ohm, but are supposed to be 3. The stock injectors are 14 ohms. I will try it out and see how it goes.

Second EDIT: The Acura Legend resistor pack works fine so far. I've put 6 track days, road racing and 1k street miles

GsLex00

iTrader: (3)

I'm having this same issue right now. JZS14, did you figure out what the problem was?

jzs14

Yeah, it had nothing to do with the resistor box or anything. When we de-pinned and removed some unused wires from the engine harness, one of the cam sensors had its wires switched (wires were switched when the plug was put back together). After trying everything we randomly depinned the wires, switched them, and the car ran great.

GsLex00

iTrader: (3)

interesting. When i was running on the stock twins my car ran good but after I switched to single thats whats giving me the problem but I havn't touched the wiring except for the resistor pack. I'm probably going to delete it like you and go 440s

jzs14

Yeah, I'm not sure why everyone runs such big injectors. I am on 440's. And I made 400whp. And that is with the fuel still turned down a decent amount on the afc neo. So at 400hp I'm not even maxing those injectors out.