1. #1
    2005 Wrangler Rubicon's Avatar
    2005 Wrangler Rubicon is offline Junior Member
    Join Date
    Jul 2009
    Posts
    10

    Causes of Ignition Coil failure??

    I recently posted a problem I was having in diagnosing multiple cylinder misfires (see http://www.jeepz.com/forum/cj-yj-tj-...y-problem.html ), which, as it turns out was the result of a failed Ignition Coil.

    Anyway, I have two quick questions on ignition coils.

    - First, what would cause the coil to fail/break?

    - Second, is there a way to manually test the 1-piece ignition coil? I ask because the technician told me that there is no way to do so, and that the coil testing is reliant on the diagnostic computer testing, which in this case, did not note a problem with the coil. He also says that this is the first 1-piece ignition coil that he has had to replace in 30 years of business.


    Thanks in advance
    Last edited by 2005 Wrangler Rubicon; 02-23-2011 at 02:58 PM.

  2. #2
    Bounty__Hunter's Avatar
    Bounty__Hunter is offline Moderator
    Join Date
    Nov 2002
    Location
    Southern Illinois
    Posts
    12,659

    Re: Causes of Ignition Coil failure??

    They fail more often than what your mechanic has seen. I know of no testing procedure.

  3. #3
    Jester32's Avatar
    Jester32 is offline Senior Member
    Join Date
    Nov 2010
    Location
    Alberta. Canada
    Posts
    1,546
    Ya I've put three in mine in the past year. But that was 160,000 kms worth lol.

  4. #4
    Ggg's Avatar
    Ggg
    Ggg is offline Senior Member
    Join Date
    May 2009
    Location
    N.W. IL.
    Posts
    525

    Re: Causes of Ignition Coil failure??

    BH can't you do an Ohm test like on old style coils?

  5. #5
    Bounty__Hunter's Avatar
    Bounty__Hunter is offline Moderator
    Join Date
    Nov 2002
    Location
    Southern Illinois
    Posts
    12,659

    Re: Causes of Ignition Coil failure??

    Don't know what the procedure would be, and electrical is not my strong point at all LOL.

  6. #6
    lambo's Avatar
    lambo is offline Senior Member
    Join Date
    Dec 2009
    Posts
    186

    Re: Causes of Ignition Coil failure??

    Just buy a new accel coil. You will get more power and better mpg,s.

  7. #7
    jfrabat's Avatar
    jfrabat is offline Senior Member
    Join Date
    Dec 2006
    Location
    San José, Costa Rica
    Posts
    1,690

    Re: Causes of Ignition Coil failure??

    I agree that they burn more often than not... I also have gone through 3 of them in the past few years... Including an Accel one and a Screaming Demon one. I just carry a spare one in the Jeep just in case now.

    '94 YJ 2.5L, Sperwinch EPi 9.0, RE 4" Std Lift, Adv. Ad. SYE, Woody Shafts, Alloy Axles, ARB Lockers, 4.88 gears, 62mm TB & Spacer, 165A Alternator, Griffin 3" Aluminum Rad, Taurus e-fan w/ DC Controller, Borla Cat-Back, Flowmaster hiflow cat, PD Ignition, 19# injectors, Adj. FPR (42PSI), MOPAR cam, Safari Snorkel, 33" BFG KM2, 15" AR wheels, Xenon H4 lights, KC Daylighters & Slimlites, Sony sound, Pavement Ends Targa Top, Hanson Front Bumper, JCR Offroad rear, AtoZ Rockers, Rhino lined Tub.

  8. #8
    Gr8tdragon's Avatar
    Gr8tdragon is offline Junior Member
    Join Date
    Apr 2010
    Posts
    24

    Re: Causes of Ignition Coil failure??

    Coils are a bunch of wire wound around a bunch of plates. The wires have a thin insulation on them as well as the plates have thin insulation separating them. Your trigger/input voltage (12- 14V) goes in on the wires. The output voltage is generated in the plates and goes out on your ignition wire to the distributor, usally 50,000 volts, low milli amps. You really can't test the coil cold as the insulation won't be failing then unless you have catastrophic failure. Then you could cut the coil open and actually see the burnt wound wire or the plates welded together. if your input voltage goes higher or lower then what the coil is rated for then you run the chance of burning out the coil, slow or fast depending on which way you change the voltage and how much you change the voltage by. If you can get a MSD coil, which I am going to buy for mine as I have used them before, the coil has a life time warranty. Sorry for the long winded electrical version.

Similar Threads

  1. Intermit Ignition Failure
    By Nomad in forum Cherokee, Commander, Wagoneer and Liberty
    Replies: 24
    Last Post: 08-27-2010, 09:18 AM
  2. TFI Ignition Upgrade - Canister Coil ???
    By RaleighDodger in forum CJ YJ TJ and JK
    Replies: 2
    Last Post: 01-31-2006, 08:49 PM
  3. Coil questions: What ignition coil works best?
    By GaryMB in forum CJ YJ TJ and JK
    Replies: 11
    Last Post: 04-18-2005, 10:29 AM
  4. Ignition module or coil???
    By JeredYJ in forum CJ YJ TJ and JK
    Replies: 6
    Last Post: 02-27-2004, 07:52 AM
  5. Ignition Coil!!!!! '93 ZJ 5.2 limited
    By willys in forum Cherokee, Commander, Wagoneer and Liberty
    Replies: 2
    Last Post: 07-20-2003, 07:00 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Log in

Log in