Connect with us

tci ignition problem

Discussion in 'General Electronics Discussion' started by kingm316, Mar 13, 2013.

Scroll to continue with content
  1. kingm316

    kingm316

    2
    0
    Mar 13, 2013
    I am new to the site and have a motorcycle ignition module that I believe is bad. I don't know if anyone here has any knowledge of ignition modules or not but I figure it is a type of electronics so I will see if anyone here can help.
    The motorcycle it came from is an 81 Yamaha virago xv750 if it helps. The ignition module is a TCI, transistor control ignition, I think is what it stands for.
    The problem I am having is one of the cylinders is cutting in and out, and I have narrowed it down to the TCI.
    I have attached a photo of the tci. each transistor grounds and opens its own ignition coil once each revolution of the engine up to probably 7,000 or 8,000 rpms.
    Based on that kind of usage what would be the most likely things to wear out. I am planning to change the transistors and wondering what else would be good to change.
    thanks for any help from anyone.
     

    Attached Files:

  2. Rleo6965

    Rleo6965

    585
    9
    Jan 22, 2012
    Its possible that you have defective power transistor and protection diode. Much better that you check using multimeter to isolate or test which of those component was shorted. Compare collector and emiiter of 2 power transistor. Transistor with very low or zero ohms reading was therefore shorted or fried.

    This TCI looks complicated with so many ic components. Possibly this have advance timing circuit.
     
  3. kingm316

    kingm316

    2
    0
    Mar 13, 2013
    there is a timing circuit in it but what I am planning is to change the transistors for sure and I was wondering about the couple of diodes and capacitors in the area of the transistors. I was wondering if someone could possibly point out which parts are the ones most likely to fail from the years of use. I would like to know so when I go to the electronic store to get the parts, I want to get everything I need to replace at one time, since it is far enough out of my way I only want to make one trip. and I don't really think radioshack would have what I need or the knowledgeable staff.
     
  4. Electrobrains

    Electrobrains

    259
    5
    Jan 2, 2012
    In general, all components that do get hot are suspicious parts.
    You could measure on the power resistors on the left side.
    Also, all electrolytic capacitors have a tendency to dry out with time and especially if the temperature is high. You could change them all, they are cheap.
     
  5. Rleo6965

    Rleo6965

    585
    9
    Jan 22, 2012
    How about post the other side of the board. It will help us more identifying possible defective components. Post bigger picture on 2 transistor side.
     
  6. THUNDERBOLT

    THUNDERBOLT

    22
    0
    Aug 29, 2010
    I had a similar issue a few years ago with a Honda. I replaced the faulty transistor and it fried again almost immediately. Before I had opened the TCI I was half hoping to understand the internals, but when I got the lid off it was just so complicated it was beyond me to try and isolate the culprit. I'm still baffled why there are so many parts in there to replace a set of contact breakers and an automatic advance / retard mechanism. I do realise the TCI advance curve will be much more refined than mechanical device can manage, but I'm bewildered by what all those components are for. I would love to hear even a brief breakdown of what is involved in such a module.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-