+ Reply to Thread
Results 1 to 5 of 5

Thread: Spark plugs keep fouling.. any ideas as to why?

  1. #1
    Supramania Regular
    suprafanatic's Avatar
    Join Date
    May 2007
    Location
    Greenwood, IN
    Posts
    1,607

    Default Spark plugs keep fouling.. any ideas as to why?

    Im currently running Autolite 3923 copper core plugs and NGK wires. i have had to replace the plugs about 3 times in one month. And now they are starting to bad agian. At least i think its the plugs. The car sounds like its sputtering and missing alot and every time i'v changed the plugs those problems went away. Then after a while the problems come back. I know my CPS wiring is bad, my car is idling around 1K some times. Any ideas what would cause the plugs to keep going bad?

    1987 Turbo Supra - built 7m- 471 RWHP - (Sold)
    1990 1JZ swapped Supra - Big single, EMS - Power unknown -(Sold)
    1990 Turbo Supra - Mostly stock for now, and very clean!

  2. #2
    Official SM Expert: Motor Oil, Lubricants & Filtration
    jdub's Avatar
    Join Date
    Feb 2006
    Location
    Valley of the Sun
    Posts
    10,734

    Default Re: Spark plugs keep fouling.. any ideas as to why?

    Try different plugs...Autolite 3923 are 1/8" shorter than spec plugs for the 7M. Give the NGK's a try.

    Do you have any ECU Codes?

    Quote Originally Posted by suprafanatic View Post
    I know my CPS wiring is bad, my car is idling around 1K some times.
    You need to get this fixed
    I will no longer respond to tech questions via PM. If you have a question, put it on the forum so everyone benefits from the answer.

    Quote Originally Posted by Supracentral
    However I still stand by my statement that 99 times out of 100, the weak link in the MKIII is the owner.
    Quote Originally Posted by jetjock
    I swear, it's like talking to an amoeba...


    Want to know about oil...read this:
    Motor Oil 101 - Dr AE Haas


    "Life is like a jar of Jalapeno Peppers
    What you do today, might Burn Your Ass Tomorrow"

  3. #3
    Supramania Regular
    suprafanatic's Avatar
    Join Date
    May 2007
    Location
    Greenwood, IN
    Posts
    1,607

    Default Re: Spark plugs keep fouling.. any ideas as to why?

    i will check for codes, thanks. also everytime i pull the plugs the arm is white, and the base around is black. if that means anything

    1987 Turbo Supra - built 7m- 471 RWHP - (Sold)
    1990 1JZ swapped Supra - Big single, EMS - Power unknown -(Sold)
    1990 Turbo Supra - Mostly stock for now, and very clean!

  4. #4
    Supramania Regular
    grimreaper's Avatar
    Join Date
    Jul 2008
    Location
    Dallas
    Posts
    2,187

    Default Re: Spark plugs keep fouling.. any ideas as to why?

    A plug can become fouled from continuous low speed driving, improper spark plug heat range (too cold), improper timing (over-retarded), too rich an air/fuel ratio or an oil leak into combustion chamber.
    what is fouling them? carbon, oil or fuel?

  5. #5
    Supramania Regular
    grimreaper's Avatar
    Join Date
    Jul 2008
    Location
    Dallas
    Posts
    2,187

    Default Re: Spark plugs keep fouling.. any ideas as to why?

    Quote Originally Posted by suprafanatic View Post
    i will check for codes, thanks. also everytime i pull the plugs the arm is white, and the base around is black. if that means anything
    Thats the ground strap, it will tell you if your heat range is correct and how your timing is. To read a plug (ive learned) you have to avoid idle and cruise if your trying to check them for wot.

+ Reply to Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Links monetized by VigLink