gas gauge light out/ misfiring cylinders

  • turtleblanket
    turtleblanket
    Junior Member
    • 1
    #1

    gas gauge light out/ misfiring cylinders

    I bought a 1984 z31 about a month ago. I have 2 main issues with it. This one is recent, but all the lights for the gas gauge stopped turning on. I don't know if its the bulbs, I have also seen people say it is the soldering that is known to go bad. My other issue is that cylinders 2, 3, 5, are all misfiring. I don't know nearly anything about cars and don't know what the issue could be. The car also has an idling issue that could be related to the cylinders misfiring, when I have the car in park or neutral the engine will rev up to 1500rpm. Are there any obvious problems that could save me from troubleshooting? The left blinker arrow also does not turn on, and the right one rarely does not work.
    Tags: 1984, digital dash, multiple cylinder misfire, non turbo
  • badq45t
    badq45t
    Senior Member
    • 300
    #2
    Do you have analog or digital dash? Clarify that, they are very different beasts

    Comment

    • turtleblanket
      #2.1
      turtleblanket commented
      04-03-2024, 11:19 AM
      sorry I always forget. I have a digital dash.
  • badq45t
    badq45t
    Senior Member
    • 300
    #3
    For you other questions, how old is the rotor cap, those wear out..for the blinkers there is a module that controls that you need to replace it. It is in the module box under the hood
  • Z_Karma
    Z_Karma
    Administrator
    • 3318
    #4
    You have multiple issues.
    1. Yes, gas gauge, assuming that you have a digital display can fail. If you're not handy with a soldering iron and flux/solder, then you can contact xenonzcar.com about repairs
    2. misfiring on specific cylinders, how was that diagnosed?
    3. The idle issue could be many things, most obvious is a vac leak somewhere under the hood.
    4. blinker arrows…the blinker arrows are intermittant, but are the exterior bulbs still flashing?

    Unfortunately, there isn't a single smoking gun for each issue you have described.

    misfires for example…could be the plug, the wire, the cap/rotor, CAS, is the injector firing, stuck valves maybe?


    84 AE/Shiro #683/Shiro #820/84 Turbo
    • 1 like

    Comment

    • turtleblanket
      #4.1
      turtleblanket commented
      04-03-2024, 11:42 AM
      I've recently found a video on how to fix the dash, https://www.youtube.com/watch?v=XTwJlwKfmzU if anyone needs it.
      The mechanic I took it to doesn't know what exactly is causing the misfiring, I am taking it to a jdm mechanic tomorrow to hopefully fix the idling, as that was expressed to be the biggest current issue.
      The exterior bulbs are fine, but its just the arrows on the dash (digital) that are not working.
  • Z_Karma
    Z_Karma
    Administrator
    • 3318
    #5
    Nice find on the video. The bulbs are probably just out for the indicator arrows.


    84 AE/Shiro #683/Shiro #820/84 Turbo
  • badq45t
    badq45t
    Senior Member
    • 300
    #6
    I had digital dash controller replaced with a recoditioned one many years ago, what the guy in the video did was something my mechanic knew back in 1990s and he had a speedo electronics shop that fixed them. The loss of my gas guage happened as wel but for ath it was cheaper to buy a new dashboard than try to fix the old one. Same shop also re-did those, it was from a Turbo (guages were slightly different) but knock on wood that fixed it. PITA to get that out and he only chaged me 2 hours of labor to remove and replace contoller, the dash was more like 3.5 hours.