Forum » EFI Tuning Fundamentals » Variable Resistor Tps RB30/26itbs

Variable Resistor Tps RB30/26itbs

EFI Tuning Fundamentals

Discussion and questions related to the course EFI Tuning Fundamentals

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Im currently in the process of tuning my N/A rb30e, with rb26 individual throttle bodys and a wade 818 cam. Microtech lt10s ecu.

the problem or difficulty im facing is load gauging, max vac is around 15 hg, max load is obviously 0hg, and the difference in throttle between 5hg, cruising) and max load, is maybe 2 or 3 load adjusting points, so the afrs are heavily fluctuating around this point when driving not under max load. I think a Variable resistor type tps as my load referencing point would be better in this setup, Wondering what tps i should use or try and retrofit? mine is factory switch type atm. any help would be greatly appreciated :)

You're absolutely right - You need to use TPS as your load input on any itb equipped engine. Is there any reason you can't just utilise the factory RB26 TPS? I've used this on every GTR I've ever tuned and it's given me no issue.

Thanks for your response, Actually i didnt have the factory tps, so used a rb30e one. i tried wiring it up to run of the auto potentiometer, but couldn't get a clean signal, even once upgraded to shielded wiring. (signal was jumpy and notchy, but worked).

I ended up adapting an LS/gm tps with an adapter plate and internal sleeve to fit, and the signal is much better, very clean and precise. i did this just because i had it available to me and didn't want to buy a brand new rb26 tps.

I think maybe my sensor was the issue here, maybe rb26 ones, or a new one would give a cleaner output?

Yea it sounds like you had a dodgy sensor which is perhaps not unlikely given the age of the RB30 now.