Spark Knock

Discussion in '80-Series Tech' started by Bear80, Nov 9, 2005.

  1. Bear80

    Bear80

    Messages:
    3,004
    Media:
    12
    Albums:
    1
    Likes Received:
    50
    Joined:
    Sep 23, 2004
    As I have been driving the 80 while installing my new lift for the mini, I have noticed a very annoying spark knock. It never spark knocks pulling up a hill or on sudden applications of throttle. The spark knock only occurs when you barely apply throttle to keep up a moderate speed, for example 30 mph or so.

    As a side note, I also noticed that my rpms drop right back to idle when I lift off the throttle regaurdless of low or high rpm and when I go back to lightly apply throttle it knocks. It seems the computer is not or cannot do anything about it. If I apply more throttle it stops. I'm thinking my issue with the rmp's dropping down is part of the problem. As I know my 22r and 3vz use a "dash pot" (?term?) to keep the rpm's from falling to fast when you lift off the throttle. I'm sure this is the same on the 1fz but anything else I should maybe look for?
     
    Last edited: Nov 10, 2005
  2. powderpig

    powderpig SILVER Star

    Messages:
    1,022
    Likes Received:
    16
    Joined:
    Jul 12, 2005
    Location:
    Boulder Foothills, CO
    Hook up a OBDII reader/computer program(they have been discussed in other threads) and take it for a drive see what is happeneing that may still be in the paramiters but not triping a code. Yes there is a dash pot on one side below the cables. May be looking for light throttle lean condition. May jsut want to check and adjust the throttle position sensor. good luck robbie
     
  3. whodat

    whodat

    Messages:
    679
    Media:
    1
    Albums:
    1
    Likes Received:
    588
    Joined:
    Sep 13, 2004
    Location:
    planets
    spark knock=pinging?
     
  4. Bear80

    Bear80

    Messages:
    3,004
    Media:
    12
    Albums:
    1
    Likes Received:
    50
    Joined:
    Sep 23, 2004
    so I can try this with a hand held OBII reader?
     
  5. powderpig

    powderpig SILVER Star

    Messages:
    1,022
    Likes Received:
    16
    Joined:
    Jul 12, 2005
    Location:
    Boulder Foothills, CO
    No hand held code reader, you need some real time data logging, like a computer based or OTC, snap on, screen based data reader. late robbie
     
  6. Bear80

    Bear80

    Messages:
    3,004
    Media:
    12
    Albums:
    1
    Likes Received:
    50
    Joined:
    Sep 23, 2004
    Well that pretty much puts it out of the question. :frown:
     
  7. tarbe

    tarbe

    Messages:
    1,490
    Likes Received:
    38
    Joined:
    Aug 6, 2004
    Location:
    Houston, Texas for now - Romance, MO soon!
    I have the exact same deal. Only goes away with 91 or better octane. I'm finishing up a tank of Chevron Supreme 93 right now and it has been nice not hearing that dang noise the past 10 days.

    I've run BG-44K, Schaeffer's Soy Ultra, Marvel Mystery oil, Seafoam (in the tank, not up the PCV) trying to clean out the carbon I suspected was the culprit. I am chicken to do the water treatment...plus I wonder now if it is carbon or something in the management systems.
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.