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Tuning Question - Post Injector Resistor Removal

jonathon

By jonathon,
in Engines & Forced Induction

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jonathon Enthusiast

jonathon

Posted
Posted

Hi all,

I've recently had some work done to my r32 gtr, (larger injectors, boost increase, adjusted cams) and have had a retune (nistune).

I've driven the car and competed in a hill climb, and all is well, however all of a sudden was unable to start the car.

After investigating- turns out the injectors are high impedance not low (was advertised as direct replacement - I guess that doesn't mean anything!). I've now removed the resistor and it's now running again.

So my long winded question is - would it need to be retuned now the injectors are getting correct ohms/power?

Or doesn't it make a difference? Was strange how it was running well for a week....

MJTru Mentor

MJTru

Posted
Posted (edited)

This is weird. I wired a power fc for a gtr to work in a gtst. I got it and it all worked good. Of course I had no vtc. What I learned was that all rb ecu wants to see a high impedance resistance. The rb25 are high impudence injectors and the gtr rb26 are low but the gtr has a resistor pack to boost the low impedance injectors to a high ohm reading. So in short all ecu's wants to see high impedance signal. I really think nissan thought peopel wouldn't get this. Lol. If you have high impedance injectors on a rb26 ecu.?? Just get rid of the resistor pack (rewire) it and you will be ok. From a resistance stand point.

Edited by MJTru
GTSBoy Grand Master

GTSBoy

Posted
Posted

Um....Marcus....that's exactly what he said and did.

OP.......Yes, retune. The opening behaviour of the injectors will be different without the resistor - effectively the latency will probably be changed the most - so it will affect light load mixtures more than high load, but still worrth doing.

jonathon Enthusiast

jonathon

Posted
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Posted

Awesome - thanks for the help guys.

Such a pain in the backside - as it only just came back from the tuner!

So are the injectors slower to open? I'd hate to be driving it running too lean...

MJTru Mentor

MJTru

Posted
Posted

Um....Marcus....that's exactly what he said and did.

OP.......Yes, retune. The opening behaviour of the injectors will be different without the resistor - effectively the latency will probably be changed the most - so it will affect light load mixtures more than high load, but still worrth doing.

Yes GTSBoy I agree thats what he was saying. I may have missed somthing tho. A rule of thumb for me is. Any mods to fuel or air should be mapped and retuned. Intresting info GTSBoy as I never thought it would affect the injectors the way you mentioned it. I will be looking into this. Also intresting to know it would make more difference in the down low area. Hmmmm

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