86 Venture TCI box problem

[ahunt2412]

Thaks in advance for any info. you can give me on this problem..

 

MY 86 Venture developed a bad TCI box last year.. Bought one on Ebay and it worked fine until just the other day.

 

I lost spark to the front cylinder and hooked my old TCI up and had spark - so I knew it was the box. Then had a family member who is an elect. tech replace diodes and resolder everything, etc. I put that reapired box on the bike and had spark all the way around and it ran fine - FOR ONE DAY! Again - i lost spark to that front cyl. He again repaired it and I now have spark to all four cylinders but have developed a "bogging down" when applying more than a couple thousand rpm's of throttle. It sits and idles fine but when applying throttle, it backfires a little and boggs down.

 

Is it just a bad TCI or did I mess up and unhook something under the airbox that is causing this or ???

 

Again - thanks if anyone can help..

 

jkit02@yahoo.com

[MasterGuns]

Could the vacuum boost sensor been left disconnected? Sounds like it may have been.

[ahunt2412]

Hmmm? WHere is the vacuum boost line you mention? Thanks

[Rocket]

Hmmm? WHere is the vacuum boost line you mention? Thanks

 

The Vacum line connects to #2 intake port & the unit is mounted beside the TCI.

Possible disconnected boost sensor wiring, from the TCI R&R?????

[dingy]

Do you have all the air box to carb connectors seated & tight.

 

This sounds a little like the running symptoms when the air box lid is off.

 

Gary

[mbrood]

I would also do an immediate OHM reading of that spark coil... They should all read in the same tolerance around 2.7 Ohms.

Edited August 13, 2010 by mbrood

[ahunt2412]

Ok... Thanks for the ideas. So far everything has checked out. I rechecked the vacuum boost hose - hooked up a spare I had around to make sure it wasn't fried, checked every imaginable hose, wire, etc, in the vicinity of the airbox and battery

and found nothing amiss or unhooked... I dont know whether to just go ahead and buy another TCi and try it or maybe I have a bad float/carb all of a sudden or what?

 

I just wasn't sure that if a TCI box is putting out spark to all cylinders, then its ok - even under load ( its backfiring slightly under throttle and bogging).

 

I'll keep after it. Getting old though. Maybe it's time to take it in?

[JoeKanuck]

The TCI does seem to be the most likely culprit. All of the other connections and such are part of the process of elimination.

 

Basically it ran ok, then like crap...was repaired, ran ok for a while then like crap. I'd hook another TCI up and see how it runs. My gut feeling is that when the diodes crapped out, they took something out along with them, something in the advance section of the box.

 

Regardless, the best way to check is plug in another box...if you can find a good working loaner.