TCI bad?

Before I get too excited about fixing my problem, I thought I'd ask for some input. I'll start with my disclaimer that I am not electronically inclined......Last week, I rode home after work on Friday (running just fine) and put the bike in the garage. On Monday, it would not start, and later discovered I was not firing on #2,3 cylinders (same coil).

I spent a good amount of time cleaning electrical connections and reconnecting with dielectric grease. My hope was that I had a bad connection, not a bad coil. Long story short, after no success with connections, I tried a spare TCI box I had, and immediately saw spark on all cylinders. So, I fired her up and she ran as good as always.

Now the question....am I overlooking something, or can I just consider the old TCI bad, and plug and play with the new one? I would hate to find out it is a temorary fix that will bite me later by ruining the new TCI.

 

Sounds pretty straight forward to me. Run the new TCI.

 

That's how I found my bad TCI. Snap in the new one and ride!

 

What they said. You could also consider pulling the old one apart and see if there's anything obviously wrong with it. If you can get it repaired, you could keep *it* as your spare.

 

Thanks, guys. I am unfortunately rebuilding my porch today, but will get the xj back together tonight. I think I will tear into the old TCI and see if anything jumps out. I saw a seam near the plugs, will it just pry apart, or do I need to cut it open?

 

What you did was THE Test for a bad TCI. Plug-in a good one and try it. Since you are up and running on the 2nd TCI ... the assumption is the other one is bad.

Put the old one back in for a Test and see if you have the problem again. If you do, you nailed it with the Spare TCI ... if not, you have further troubleshooting to do.

 

On mine, I think it was four screws that held the back plate on. Once that's off, you'll need to unsolder the four leads that connect the plug to the circuit board. The guts should pop out after that.

 

For TCI repair visit the Kool Kiwi's site,(Dave Jackson) here:
http://members.tripod.com/dave_jack/id41.htm

 

I recently repaired my turbo TCI - I replaced the transistors and away I went. It did take me buying another TCI to confirm that it was the problem though.

 

It indeed are the 2x switching transistors inside the TCI that fail the soonest.. Get a pair of equivalent darlingtons, then no reason it shouldn't live again. if find difficulty locating compatible ones, PM me the original transistor id & i'll forward you a list of the compatible ones you can get easily in your area.

 

Thanks for the tips and links! Maan, I will PM you when I have a chance to pull it apart, as I had to look up what "darlingtons" are (ie, I may need some assistance!), thanks! I still haven't figured out how to get it apart as mine is completely sealed (xj700). I still haven't tried to pry at the only seam I can see between the main box and the plate that has the connections. I assume the top will come off it I can get something in there to pry it. If a strong knife blade won't do it, I might try making a knotch with a dremel wide enough for a screwdriver blade. I'm just glad that the money I spend on the extra CDI finally paid off after sitting in the drawer for so many years!

 

Large Hammer?
Small Thermonuclear Device?
Ask it "Pretty Please"?

And if all else fails FOUL LANGUAGE!

I have a full box of bad language I've been saving up if you need it.
Plenty of 13 and 17 letter words ending in "er".

 

HE HE. Foul language is my favorite tool. Works on everything from baking to construction!

 

You guys who can crack-open a TCI and identify the components inside it are great.

How do you know what needs to be replaced inside the TCI? Is there "A look" about a bad Transistor or are they cheap enough to just go ahead and replace one or more without testing it?

What's the Bottom Line Cost for Re-transistoring a TCI Unit?

 

One failed attempt at learning to fix radios for the Marines will do that to a person.

The transistors shouldn't be more than a few bucks each, if that. The problem with mine, as described on the above-referenced page, wasn't the transistors, but the electrolytic capacitors. The most expensive bit wasn't the components, but the can of spray-on circuit board sealant.

How did I know what to replace? The symptoms listed on the page matched mine to a tee. He said his problem was capacitors, so I replaced them.

 

I will likely be taking the schmuckaholic approach and just replace the pieces recommended. At this point, I don't have anything to lose, so why not give it a shot.

Thanks for all your input. I'm taking our 5 month old daughter on her first trip to the zoo today, so cracking open the TCI will have to wait until later. Gotta have priorities! Have a great new year, guys!

 

So,

Where and at what cost can a fellow find spare TCI's, new or good used ones?

Thanks,

Phil

 

Funny how you learn something every day. I was told, back when I was riding a Virago and the TCI went South ... that they were filled and SEALED with some impenetrable Sealant that made servicing them impossible.

I'll never forget tossing that Box in the trash thinking it was cooked ... and, now I hear that for a few bucks it could have been refurbished and kept as a Spare.

 

Hi Phil, I have a good used TCI for your bike, I sent you a PM. Just out of curiosity, why do you think your unit is bad?

 

Hi Chacal,

I really don't think there is anything wrong with the one in the bike now. From what I'm reading it is a rather critical part so I thought, in whats left of my mind >), that it may not be a bad idea to have a spare, if they are affordable. I did find out how to rebuild them. With me, a small dose of knowledge can be a very dangerous thing. >)

Off to check my PMs,

Phil