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HybridZ
wigenOut-S30

AFR all over the place with Denso 195500-1350 RX7 injectors

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Hey HybridZ !   I am running a L28ET with JE pistons nismo HG T3/t4 50 trim turbo .. Mega squirt 1 extra rev 029V with Tuner Studio MS v3.0.10

 

I used to run Supra Mk3 turbo 440CC injectors (low emp)  and switched over to these Denso 19550-1350 RX7 NA 460CC injectors  (low emp).. I sent them to be flowed and cleaned. They all tested good and actually flowed 492 @2.25 bar fuel pressure..  However  when crusing the AFR is hunting and never really stabilizes.. I set the required fuel for 460CC and I played with the Injector open time and the PWM under required fuel.  With the Supra injectors I had the open time at 1.2ms same as the PWM.  It does not seem to matter much if I change it to 1.0 , 1.2 or 1.3ms with these .. I have searched and searched and cannot find the dead time for these Denso Rx7 injectors.. They are Pintle style and I think the Supras were (disk with multiple holes ) has anyone had any experience with running these Rx7 injectors and tuning with them?   at 25% throttle and at WOT they seem to have stable AFR right at what I am tuning for.   

 

Thanks for any help!

 

 

 

 

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Did you actually measure the resistance of the injectors with an Ohm meter? That particular Denso injector  came in both high and low impedance versions. Both with the same Part number. Don't go by colors ( Red or Purple )  as that can change from heat soak on used Injectors.

 

http://www.robietherobot.com/storm/fuelinjectorguide.htm

 

http://www.rotaryresurrection.com/rotary%20pages/injector%20folder/injector.html

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I would still recommend testing and measuring your deadtime. When running small injectors its not a big deal but the closer you are to deadtime the larger the error.

 

It's not a magic number you can just find online, it changes depending on your driver circuitry, wiring, grounding, other EMI devices on the 12v. 

 

Follow this guide: 

 

If you dont have graduated cylinders you can also weigh the fuel mass. That's what i did. 250g for each pulse width. 

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