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Injector Resistance.


Fubar231

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Got a question about injectors and there resistance.

Theres low impedence and high impedence.

 

Ive heard you can use high impedence injectors in a low impedence system, but you can not use low impedence injectors in a high impedence system. Is this correct? Just curious because im trying to buy some injectors, but the ones this guy is offering me are high impedence, but our cars use low impedence, but he says he ran them for 2 years fine and just went to a bigger injector. I would just like to hear from someone else who isnt trying to sell me the item.

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edit. here is info for you!

 

http://www.hondata.com/techlowohminjectors.html

 

Injector temperature

 

Not only do the injector drivers get hot, but the injectors themselves heat up from the current passing through them. We ran one three minute test with the injectors in open air and not being cooled by water.

 

* After 3 minutes the stock injectors were 40 degrees C.

* After 3 minutes the 2.5 ohm injectors were 100 degrees C

 

Injectors are normally cooled by fuel. What these figures show is that the 2.5 ohm injectors without a resistor pack run hotter heat the and fuel more than stock injectors.

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See, this is all about using low impedance injectors without a resistor, were using high impedance with, (Or removing) without the resistor. I assume without the resistor they will be fine, But the MK3 TCCS needs the resistor clip to be connected, so there would have to be a clip made with looping wires to fool the ecu.

Conclusions

 

  • Running low impedance injectors without a resistor box will substantially increase the temperature of the transistor driver IC due to the increase in current flow.
  • The temperature increase will depend on your driving.
  • If that temperature remains high enough for long enough the driver transistor will be damaged.

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Do you have a resistor pack anywhere? The only concern I can think of is if the injector driver is sending out enough current to fire the injectors. The drivers are expecting low impedance injectors, and if hit an injector with 5 to 6 x the resistance, the current's going to drop by that much. The injectors either won't fire, or they'll fire partially and sporadically.

 

edit: on a honda, cutting out the resistor pack is as simple as cutting all 5 wires going into the resistor box and twisting them all together. The high impedance injectors take its place, and the ECU goes about its business like normal. I'd imagine the same is true for a supra, but I dunno.

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on the early hondas, you remove the resistor box to run the later high impedance ones.

 

the resistor on those, can be removed, and a clip from another resistor box cut up, and all the wires tied together.bypassing the resistor.

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I have a resistor pack stock, but the car wont start unless its plugged in. The mk3 tccs will not allow the car to start unless its plugged in, so, what i read in the technical sections on different supra forums, is that people get a plug thats the same type, connect it and just run a lead wire to make it think its plugged in. I got a post going on a diff forum right now and im waiting for some of the smarter ones to get back to me.

 

Ninja Edit: Damn rob way to post at the same time as me, douche...

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edit: on a honda, cutting out the resistor pack is as simple as cutting all 5 wires going into the resistor box and twisting them all together. The high impedance injectors take its place, and the ECU goes about its business like normal. I'd imagine the same is true for a supra, but I dunno.

 

thats what im saying

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Yeah, you'd think so. Read some weird shit about my ecu being a crazy bitch. Some people couldnt get there cars to start after they bypassed the resistor, because the tccs needs a signal voltage from it. So what they did was just make a lead wire and looped it or something. AT LEAST thats what i have read in the technical sections. Ill get back to this later.
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I doubt there's any feedback to the ECU from the resistor box, unless it's tied to some other function in the car. How many wires are going to it?

 

Not sure, kinda out of it right now so ill go look at it tomorrow, or try to find the thread i was looking at on the supra forums and quote them.

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