Results 1 to 12 of 12

Thread: Fuel injection resistor

  1. #1
    LXi User firefighterwhite89's Avatar
    Join Date
    Jul 2009
    Vehicle
    1986 Honda Accord LXi(Rebuilt)
    Location
    Somerville, Alabama
    Posts
    787

    Fuel injection resistor

    All plugs on my fuel injection resistor read 9.3 Ohms across the board. IIRC resistance should be 5-7 Ohms. What would cause this to be slightly higher in resistance? Could it be dirty terminals? Or maybe a short?
    Shaggy
    FF II/ETC I


    "What's my age again? What's my age again?"



  2. #2
    3Geez Veteran lostforawhile's Avatar
    Join Date
    Dec 2002
    Vehicle
    86 hatchback, 1990 Lincoln Towncar
    Location
    nowhere GA
    Posts
    15,401

    Re: Fuel injection resistor

    thats not much to worry about, even a small amount of resistance at the leads could cause that, you are mainly looking for one that is a lot different then the others. Since they are all the same, I wouldn't worry about it

  3. #3
    SEi User gp02a0083's Avatar
    Join Date
    Nov 2004
    Vehicle
    1989 Lx-i Hatchback
    Location
    Jackson, NJ
    Posts
    1,838

    Re: Fuel injection resistor

    Quote Originally Posted by firefighterwhite89 View Post
    All plugs on my fuel injection resistor read 9.3 Ohms across the board. IIRC resistance should be 5-7 Ohms. What would cause this to be slightly higher in resistance? Could it be dirty terminals? Or maybe a short?
    If you encountered dirty terminals or bad connections with the multi meter probe tips your resistance measurements can swing a bit, having all measurements reading the same can rule out bad connection. A short would typically read as an open or low resistance below 1 ohm. Most likely the cause of the increase in the resistance is due to age, material fatigue, thermal degradation which would be normal for a 20+ year old part and also reading similar resistances. regardless I would suggest to replace the box

    Quote Originally Posted by lostforawhile View Post
    thats not much to worry about, even a small amount of resistance at the leads could cause that, you are mainly looking for one that is a lot different then the others. Since they are all the same, I wouldn't worry about it
    First of all if they all match @ 9.3 ohm, all that indicates is that the resistance increase is not isolated to one particular portion of this resistor array. However this still, exceeds the 5-7 ohm factory spec by 24%-46%, outside the tolerance rating for the resistors. Second, the increase in resistance would have an effect on the drive current required to open the injector properly when using the same pulse width signal, to little current and the injector has opening / on-time ends up with lag or doesn't work at all. Third, resistors can end up having a dynamic resistance characteristic when overstressed and /or damaged in an operating circuit, I see things like this readily on my Lab bench with 600V circuits. If the resistor is unable to hold its resistance value within its spec this can cause a problem and can damage the injector and possibly the ecu's drivers. Interconnects of any type are always suspect to contact issues, however a good contact should always be below 1 ohm.

    1989 Accord Lx-i hatchback (current DD project)
    1986 Olds Cutlass 442 clone (never ending project)
    3Geez resident body man
    Owner of Wreck-less auto body

  4. #4
    LXi User firefighterwhite89's Avatar
    Join Date
    Jul 2009
    Vehicle
    1986 Honda Accord LXi(Rebuilt)
    Location
    Somerville, Alabama
    Posts
    787

    Re: Fuel injection resistor

    Is the resistor box something I can simply pursuede open and replace 4 resistors, our too much of a hassle to even fool with? Bear in mind I live in the country where 90% of the vehicles driven around here is the American made hunks of junk hence the oldest model Hondas I can find are `97+...and ordering the part new without going to a dealership is pretty much impossible. So if I have to dremel the box open, replace some electronic parts and jb weld the protective case back together, that's what will happen. I'm definitely not as lucky as the western coast guys. Seems most southerners are all 'Made in America!' Type douches when it comes to vehicles.
    Last edited by firefighterwhite89; 12-12-2014 at 08:35 AM.
    Shaggy
    FF II/ETC I


    "What's my age again? What's my age again?"

  5. #5
    LXi User firefighterwhite89's Avatar
    Join Date
    Jul 2009
    Vehicle
    1986 Honda Accord LXi(Rebuilt)
    Location
    Somerville, Alabama
    Posts
    787

    Re: Fuel injection resistor

    I think this may be the reason behind my injection issues. Cold or not, it still idles somewhat rougher than it should.
    Shaggy
    FF II/ETC I


    "What's my age again? What's my age again?"

  6. #6

    cygnus x-1's Avatar
    Join Date
    Aug 2006
    Vehicle
    '87 Prelude DX, '00 Nissan Frontier, '87 Suzuki Samurai DIESEL!
    Location
    Chicago area
    Posts
    2,267

    Re: Fuel injection resistor

    Before yo do anything else, touch the probes together on your meter and see what it reads. Subtract that number from what you read on the resistor box. Some meters are not very accurate at measuring low resistances. I had one years ago that added an extra 2-3 ohms.

    C|

  7. #7
    LXi User firefighterwhite89's Avatar
    Join Date
    Jul 2009
    Vehicle
    1986 Honda Accord LXi(Rebuilt)
    Location
    Somerville, Alabama
    Posts
    787

    Re: Fuel injection resistor

    If I subtract 4.3Ohm from 9.3Ohm I get right at five ohms. Is this how you're supposed to test it? Should I go to radio shack and test a few resistors for accuracy? It is a cheap multimeter. Came from harbor freight for $7
    Shaggy
    FF II/ETC I


    "What's my age again? What's my age again?"

  8. #8
    LXi User firefighterwhite89's Avatar
    Join Date
    Jul 2009
    Vehicle
    1986 Honda Accord LXi(Rebuilt)
    Location
    Somerville, Alabama
    Posts
    787

    Re: Fuel injection resistor

    I get what you mean. When touching the probes together I get between 40.5&18.9ohms resistance depending on where on the probes I cross them...wtf?
    Shaggy
    FF II/ETC I


    "What's my age again? What's my age again?"

  9. #9
    LXi User firefighterwhite89's Avatar
    Join Date
    Jul 2009
    Vehicle
    1986 Honda Accord LXi(Rebuilt)
    Location
    Somerville, Alabama
    Posts
    787

    Re: Fuel injection resistor

    My multimeter is on 200 ohms setting. Should I have it on another?
    Shaggy
    FF II/ETC I


    "What's my age again? What's my age again?"

  10. #10
    3Geez Veteran lostforawhile's Avatar
    Join Date
    Dec 2002
    Vehicle
    86 hatchback, 1990 Lincoln Towncar
    Location
    nowhere GA
    Posts
    15,401

    Re: Fuel injection resistor

    Quote Originally Posted by firefighterwhite89 View Post
    My multimeter is on 200 ohms setting. Should I have it on another?
    I think you are fine, those type of power resistors can be off an ohm or two anyway, and still be within tolerance, the fact that they are all consistent is more telling

  11. #11

    cygnus x-1's Avatar
    Join Date
    Aug 2006
    Vehicle
    '87 Prelude DX, '00 Nissan Frontier, '87 Suzuki Samurai DIESEL!
    Location
    Chicago area
    Posts
    2,267

    Re: Fuel injection resistor

    Sometimes the outsides of the probes get dirty and don't make a good connection. It helps sometimes to rub them together a few times and then hold. You should be using the lowest setting there is, probably 200 ohm.

    I'm with lost on this one. If they all measure the same they're probably ok.

    C|

  12. #12
    LXi User firefighterwhite89's Avatar
    Join Date
    Jul 2009
    Vehicle
    1986 Honda Accord LXi(Rebuilt)
    Location
    Somerville, Alabama
    Posts
    787

    Re: Fuel injection resistor

    Excellent. Thank you gentlemen.
    Shaggy
    FF II/ETC I


    "What's my age again? What's my age again?"

Similar Threads

  1. Replies: 0
    Last Post: 03-07-2012, 02:07 PM
  2. webers or fuel injection?
    By stephensimmons in forum Performance
    Replies: 53
    Last Post: 03-11-2010, 03:41 AM
  3. RC Fuel Injection
    By Pico in forum Performance
    Replies: 15
    Last Post: 08-14-2008, 10:38 AM
  4. Fuel Injection
    By igarut5410 in forum Forced Induction
    Replies: 10
    Last Post: 03-27-2007, 05:48 PM
  5. fuel injection swap
    By SlammedAccord89 in forum 3geez Accords
    Replies: 3
    Last Post: 12-28-2003, 07:38 PM

Bookmarks

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
  •  
This website uses cookies
We use cookies to store session information to facilitate remembering your login information, to allow you to save website preferences, to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.
     
Links monetized by VigLink