Nistuning an 86 N/A ecu on an 86T

  • #1

    Nistuning an 86 N/A ecu on an 86T

    Hey, I have an 86T that I'm putting nistune in. I needed a donor ecu for nistune and the only one I found at the junkyard is an 86 N/A. I'm wondering if I'll have any issues using it. Does anyone know if the o2 sensors are the same between turbo and n/a ecus? I thought I read somewhere that they are different, but checking redz31, it says they're the same. I know the n/a doesn't have the knock sensor but it sounds like I should be fine without it correct?

    And any idea if in theory I can run the n/a ecu in my turbo before I can get my nistune board soldered in? Because I tried that just to make sure the car would fire up and it did, except it just runs 10 AFRs no matter what I do, cruising or full boost. I'm just concerned that once nistune is in it may super rich if something else is going on.
    I do recall with my old ecu if I disconnected the o2 sensor it ran 10AFRs while cruising or full boost. I'm concerned my o2 sensor could be causing problems, i've had issues with it in the past. Can Nistune be run without a stock narrowband? I know my 0-1V output on my wideband won't work since the stock one reads resistance.

    Thanks for the help
    1986 300zx Turbo
  • #2
    It shouldn't be a problem. Once you have Nistune installed you can load the stock turbo map to the computer and run on that. The O2 sensors for 86T and NA are the same. http://www.redz31.net/pages/fuel.html The knock sensor doesn't really make any difference, it doesn't read above 3k rpm anyway, so it doesn't really do any good.

    I suppose you could run on the NA ECU, but as you've seen you're going to run really really rich because the injectors are bigger than what the ECU is tuned for. Honestly, at the end of it all, the O2 sensor doesn't really matter. You're probably better off just unplugging it if you're in an area that you can get away with it (no emissions tests). The car will run fine with it if it's working fine, and it will run fine if the O2 is unplugged, but it will have all kinds of weird issues if the O2 goes bad. If you're at a point you're installing Nistune, then you need to be running a wideband anyway. What are you trying to accomplish by getting Nistune? Are you changing to larger injectors or something?
    Prius… because Pretentious wouldn't fit across the back of the car…

    Cheap, Fast, Reliable - pick any two

    My 1986 Turbo Build
  • #3
    Ok awesome, that's good to hear. Yeah my Nistune has a stock turbo map on it. And that's the page I read too, just wanted to make sure. Glad to hear about the knock sensor too, that's pretty much what I was reading as well.

    I don't plan on actually driving around with the NA ecu, I just put it in to test the ecu and make sure it works. But I didn't even think about the fact that it's tuned for way smaller injectors, that totally explains it. That's good to hear.
    So you say unplugging the o2 sensor will make it run fine, is that only with nistune, or with the stock turbo ecu? Because my last ecu ran decent, but if I unplugged the o2 sensor my AFRs dropped down to 10s while cruising or full throttle? Is that normal?
    I'm using Nistune because my old ecu wasn't fueling very good(12-13AFR) cruising and would lean out really bad if I was boosting stock boost. So something I can control would be great. And shortly down the road I will be getting a bigger turbo and injectors. Oh and I already have a wideband, AEM.
    1986 300zx Turbo
  • #4
    If the car runs fine with the O2 hooked up I wouldn't worry about it, but no, the car doesn't really need the O2 sensor. I've been running mine without one for a long while. I just have my wideband sensor stuck in the stock bung. But then I have Nistune and 450cc injectors, so I have no idea what adding a functional O2 would do in my case.
    Prius… because Pretentious wouldn't fit across the back of the car…

    Cheap, Fast, Reliable - pick any two

    My 1986 Turbo Build
  • #5
    well it ran ok with the o2 sensor in, but for sure not right. so either way was bad, thats why i bought nistune. hmm well i guess once nistune is in ill find out if it will run fine like yours. thanks for the info
    1986 300zx Turbo
  • #6
    Nistune isn't going to magically make it run fine. It took a lot of tweaking and tuning to get mine to run the way that it does. I wouldn't even be running Nistune if I hadn't upgraded my injectors. You may be better off looking for a known good 86T or 87T ECU and running your car off of that.
    Prius… because Pretentious wouldn't fit across the back of the car…

    Cheap, Fast, Reliable - pick any two

    My 1986 Turbo Build
  • #7
    Yeah I figured that, but considering the ecus I've had in the past it should be pretty good. Plus I certainly will need it in the future, that's why I went that route. I will have bigger injectors and turbo. I realize it will take some tweaking. But it have a real time readout of the sensors right? That can at least help diagnose some things
    1986 300zx Turbo
  • #8
    Which sensors?
    Prius… because Pretentious wouldn't fit across the back of the car…

    Cheap, Fast, Reliable - pick any two

    My 1986 Turbo Build