Bringing TBI and Multi Port Fuel Injection to a New Level.     EFI Conversions and Tuning! Seattle to Portland! E-mail Tuning Consultant!
Results 1 to 5 of 5

Thread: Tbi ignition module failure

  1. #1
    Carb and Points!
    Join Date
    Jul 2020

    Tbi ignition module failure

    Hi All
    I had a strange failure with a new ignition module yesterday
    it is running on a 1227747 with the stock coil
    I put heaps of heat paste on it but the car popped at high revs then a minute later stopped and would not restart.
    I checked the coil and initially thought it was that but fitted a new coil and it did not help.
    hooked a noid light up to the coil power and signal from the ignition module and I had no pulse.
    the strange thing is I still have injector pulse.
    I have disconnected the 4 wire plug that goes to the Ecm and still have no spark.
    I disconnected the tach and still no good.
    I am pretty sure the module is cooked but was concerned something else caused it but all the wiring checks out ok.
    is it possible a tacho could burn out the ignition module?
    The engine is a v8 and in a car that was originally a v6
    I am using the stock v6 tacho with a Dakota digital tach converter to change the pulses for the tacho.
    the dakota module part number is SGI-8 E.

  2. #2
    Fuel Injected! PlayingWithTBI's Avatar
    Join Date
    Dec 2018
    What brand ICM do you have? There's a lot of folks that found cheap modules don't last long. I was just looking at reviews such as these, too many ICM failures on new equipment.

    Try AC Delco, Delphi, or Davis Unified Ignition (DUI)

  3. #3
    Fuel Injected!
    Join Date
    May 2019
    Quote Originally Posted by Sheponaro View Post
    I checked the coil and initially thought it was that but fitted a new coil and it did not help.
    A defective coil could definitely damage an ignition module and as PlayingWithTBI pointed out, many of the new replacements are junk. It's unlikely that the tach caused the problem, but if the wire from the coil to the tach adapter shorted to 12v power, that would take out the module. Based on what you've said, it's more likely that the coil killed the original module and it's replacement.

  4. #4
    Fuel Injected!
    Join Date
    Oct 2013
    Well, the module has circuitry that detects and conditions the signal from the pickup coil. One pulse per ignition firing. These pulses are fed as the reference to the ECM and the ECM uses these pulses as the basis for all the rpm calculations and injector firing.

    The module has more circuitry that will switch between using the conditioned pules or the ECM timing output and fire the coil. It is switched by the bypass signal from the ECM. The module will fire the coil at the fixed base timing until the ECU asserts the bypass and takes over timing duty. Then, the timing pulses come from the ECU on the EST wire.

    After this switch circuitry, the module has the actual coil driver that drives the coil.

    So, yes it's very possible the switch or coil driver part of the circuit has failed and the ECM can still get ignition pulses and fire the injectors.

  5. #5
    Carb and Points!
    Join Date
    Jul 2020
    Thanks for the replies everyone, as I am in Australia the only ICM I could get locally was a Tridon brand that is most definitely cheap chinese. I have since ordered a coil and ICM from the over there it is all AC delco branded so hopefully better quality.

Similar Threads

  1. TBI ignition control module
    By typhoonss in forum GM EFI Systems
    Replies: 11
    Last Post: 04-11-2018, 05:18 AM
  2. GM Ignition Module control
    By neruve in forum GM EFI Systems
    Replies: 1
    Last Post: 02-02-2016, 12:02 AM
  3. Looking for original 369 Ignition control module
    By joegreen in forum Buy - Sell - Trade - Wanted
    Replies: 2
    Last Post: 10-12-2014, 12:39 AM
  4. 16188051 with DIS ignition module?
    By brian89gp in forum GM EFI Systems
    Replies: 5
    Last Post: 08-13-2013, 03:58 AM
  5. Connector for 5 pin side of ignition module???
    By Blazer3664 in forum GM EFI Systems
    Replies: 0
    Last Post: 05-29-2013, 04:47 AM

Tags for this Thread


Posting Permissions

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