Results 1 to 11 of 11

Thread: s13 rb25 tach install bs

  1. #1
    Apprentice suislideSC's Avatar

    Join Date
    Feb 2011
    Location
    Athens, GA
    Posts
    862

    Default s13 rb25 tach install bs

    so i'm already not a fan of my boost gauge on the pillar, and my regular tach doesn't work so i'm using the extra spot under my boost gauge for a tach.
    THE PROBLEM: The signal wire. Tried the RB signal wire(pin 7 on the ecu) no dice.
    -A known easy fix?
    -Is there a way to wire it somewhere else on the ecu?
    -If not, think it will work to ghetto rig a wire to each individual coil in series? (pins 1-3 & 11-13)

  2. #2
    WillWork4Tires ka-titties's Avatar

    Join Date
    Sep 2007
    Location
    TLC 4 Lyf
    Posts
    11,047

    Default

    i dont know about RB ecu's but i just wired up an autometer tach for my KA and the KA ecu has an RPM test output that outputs an RPM signal. works excellently. your shit is probably different though because its coil on plug.

  3. #3
    Platinum Member spitefulCheerio's Avatar

    Join Date
    Sep 2009
    Location
    MiataLand
    Posts
    5,688

    Default

    COP setups usually have a wire coming off the coil for cylinder one that gives off a tach signal. Had to wire up a shift light in my cobalt this way. Look up which wire it is going to the coil and splice it in
    1998 V6 Mustang: Sold!
    2005 Cobalt SS/SC: Meth Kills
    2001 Miata SE: NB4L

  4. #4
    Apprentice suislideSC's Avatar

    Join Date
    Feb 2011
    Location
    Athens, GA
    Posts
    862

    Default

    Quote Originally Posted by ka-titties View Post
    i dont know about RB ecu's but i just wired up an autometer tach for my KA and the KA ecu has an RPM test output that outputs an RPM signal. works excellently. your shit is probably different though because its coil on plug.
    does have this, but it doesn't have any signal somehow. spent a few hours reading, seems like a very common problem to not have signal there either. ghey..

  5. #5
    Apprentice suislideSC's Avatar

    Join Date
    Feb 2011
    Location
    Athens, GA
    Posts
    862

    Default

    Quote Originally Posted by spitefulCheerio View Post
    COP setups usually have a wire coming off the coil for cylinder one that gives off a tach signal. Had to wire up a shift light in my cobalt this way. Look up which wire it is going to the coil and splice it in
    http://wiki.r31skylineclub.com/images/7/72/RB25DET_ECU_Pinouts.jpg
    h
    ere is the pinout diagram btw.
    Do you mean the wire for cylinder one's coil itself(pin 1) or a separate wire all together?
    couldn't find anything obvious on the diagram.

  6. #6
    WillWork4Tires ka-titties's Avatar

    Join Date
    Sep 2007
    Location
    TLC 4 Lyf
    Posts
    11,047

    Default

    trace where the signal wire for coil number 1 goes to the ecu plug

  7. #7
    Apprentice suislideSC's Avatar

    Join Date
    Feb 2011
    Location
    Athens, GA
    Posts
    862

    Default

    i mounted the tach up, with power, and ran a wire over to the ecu and tucked it, so tomorrow when there's sunlight i can just open it back up and see if that works.

  8. #8
    Platinum Member spitefulCheerio's Avatar

    Join Date
    Sep 2009
    Location
    MiataLand
    Posts
    5,688

    Default

    The coil for cylinder 1 should have at least 3 wires going to it. How many are going into yours? One of those wires going into the coil *should* have a tach signal. Trace all the wires from the coilpack back to their origins. One of them will be it, hopefully
    1998 V6 Mustang: Sold!
    2005 Cobalt SS/SC: Meth Kills
    2001 Miata SE: NB4L

  9. #9
    Apprentice suislideSC's Avatar

    Join Date
    Feb 2011
    Location
    Athens, GA
    Posts
    862

    Default

    No luck yet still. I went with cheerio and dimitri's suggestion, more specifically:

    Every cylinder has has three wires going to it, here is number 1:
    http://suxorz.com/?v=photonmn.jpg
    ^ you can also see how cylinder 2 also has 3 wires (as do all)
    youve got black(ground) and white(12v) on every coil + the specific ignition wire for each.

    following the wire up to the harness there is a connector. cyl 1 is the 3rd from the left.
    http://suxorz.com/?v=photo1srs.jpg

    It goes in as a yellowish/black and comes out orange/blue (bottom row 3rd from left)
    http://suxorz.com/?v=photo2jrj.jpg

    So back to the ecu it goes to this pin. Checking the diagram from the above posts confirms that it is indeed the "cyl 1 spark"
    http://suxorz.com/?v=photo3.jpg

    I attached the signal wire to coil 1, cranked it up, nothing.
    also tried coil 6 just to see, cranked it, nothing.

    previously as I said i've tried the tach signal out wire which is most likely fried in the ecu.
    thinking about opening up the ecu and doing some resolder if necessary.... and if i can find a soldering gun

    anyways. great suggestion (+rep)
    next plz? lol
    Last edited by suislideSC; 09-19-2011 at 02:12 PM.

  10. #10
    WillWork4Tires ka-titties's Avatar

    Join Date
    Sep 2007
    Location
    TLC 4 Lyf
    Posts
    11,047

    Default

    what tach are you using?

  11. #11
    Apprentice suislideSC's Avatar

    Join Date
    Feb 2011
    Location
    Athens, GA
    Posts
    862

    Default

    This cheap chinese POS.
    http://www.gofastforless.com/junk/Tach2.jpg
    It was hooked up in my rb20 car and worked fine for 5 years though. The previous owner of that car had it installed so not sure how they did it.

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
  •