I've got a miss....

[timgray]

Went on a ride today. Hoped to get in maybe 400 miles. After about 100 miles I started to get a backfile at idle when I would slow down into small towns, then it got progressively worse..

 

Zero power at idle, in order to take off from a stop you have to rev it to 2000 rpm. turned around to head home. It has power and feels right at highway speeds, by the time I got home, it was kicking in and out at highway speed and I'm getting surging as if a cyl is working, not working, working, not working....

 

At idle, it's popping like crazy and idling very poorly.

 

Am I losing a coil? or is it the Ignition computer that needs some TLC?

 

83 std, well maintained, I do not have any ground wire upgrades. It does start a bit hard when hot.

[Yammer Dan]

TCI?? Clean connections first.

[Thom]

Yep ! sounds like tci Dans rite clean the tci plug , did you just wash the bike in the last few days or ride in the rain ? you mite have a wet tci , need to bake it , remove the tci , remove cover , heat it in oven at 150 degrees for a hour , that should dry it out .

[timgray]

If I dig out the TCI to check the connections should I just go ahead and relocated it/ re solder it? or is it easy to check the connections without digging it out from under the airbox?

[Thom]

relocate on top of your air box , it will stay dryer and it will be easyer next time , a resoder won't hurt as long as you have it out .

[Yammer Dan]

If I dig out the TCI to check the connections should I just go ahead and relocated it/ re solder it? or is it easy to check the connections without digging it out from under the airbox?

 

 

You don't have to dig it out to check connections. Just pull air box. If you do dig it out its time to relocate. Mine started acting up on my 85 first day I owned it washing with garden hose and lousy pressure.

[timgray]

Anyone have links to the easy way to pull and replace the airbox? I heard it's a nightmare to try and get everything back on when you pull it.

[Yammer Dan]

Need a long set of needle nose for hoses on bottom. Just watch it and it is not too bad.

[Thom]

i can tell you how i got mine out BUT IT IS NOT THE WAY TO REMOVE IT , ok now the way i got mine out , if you remove the side fairing than break your neck look up at the tci you will see 2 screws holding it in , 1 of them i got out , lets just say that i am missing a ear that the other screw was in but if your going to pull the tci Now is the time to change the spark plug leads .

[timgray]

Tore into it today. wow that airbox comes off easily. and Wow how am I going to get that vent tube back on.

I have no spark on #3 and a weak spark on #4. #1 and #2 look like they have a good strong spark.

 

 

Anyways, got to the Ignition module. Connectors look as clean as new, I sprayed some contact cleaner anyways and added some dielectric grease to make sure they never corrode. restarted the bike and nope. Still no spark on 3 and weak on 4.

 

So does that mean I have a dead coil and a failing coil? If so is there any replacements that are better than a used 25 year old part off ebay? Like a vmax coil?

[Yammer Dan]

Pick-up coil maybe? This is the ones in the Strator housing. Lot of guys on here with more knowledge of this than I have. Just my thoughts because 2 of them are failing. Come on guys I want to hear this one too. And while we are here how important is it to maybe clean those Pick-up coils once in a while? Involves opening housing that could end up with leak but I have been wanting to do this one.

[Squeeze]

Sounds very much like the Pick-Up Coils are giving up.

 

Find the 5 Wire Connector at Frame at about below where your left Knee is when sitting on the Bike and check their Resistances according to the Manual.

[Dano]

You need to get a digital meter to check the inputs and outputs to/from the TCI. Give me a call when you're ready to check it, I'll guide you thru the process (317-370-0139 cell) If it was a pick-up coil, it would be 2/4 or 1/3 cylinders.. This is the only way I found my problem, which was a loose terminal connection on the output of the TCI to #3 coil........ Terminal wasn't making contact with the pin out from the TCI. Relocate that sucker using a #3 phillips bit, 1/4" drive ratchet and 1/4" socket. Twist your head around down in the airbox area, there's one screw on each side (upside down). You'll have to hold that ratchet head up tite on the screw or you'll strip it. Once you get it broke loose it's easy. Unplug it, bring your harness up top and the wires are just long enuff to relocate TCI to the top of the airbox. Cleans up 50% of the problems, plus its easier to diagnose.

On the airbox reinstall, put the big hose on the airbox, wiggle it back down between the carbs then use the looooong needle nose to put the hose back on the twinkie. I used a screw clamp instead of the spring clamp to hold it on there.

 

Good luck

[Venturous Randy]

Let me throw you another curve. How old are your spark plug caps? I ask this because I spent a good part of a day tracing down a miss on a friends 89 and it ended up being a corroded resistor in the spark plug cap.

RandyA

[Yammer Dan]

Another good one.

[timgray]

As far as I know the spark plug caps are as old as the bike, but they look like a set of New old stock. clean inside as if the bike came off the showroom floor 6 weeks ago. All the electrical on this bike looks that way. when I unplug anything.

 

I can take one apart, what should they measure with an ohm meter?

[MiCarl]

Tim,

 

No spark can be one of 3 things:

 

Coil

Pickup

TCI

 

Quick and dirty test on the coil is to swap leads with another, see if it fires.

 

The pickup coils can be checked with an ohm meter. The wire pairs and the spec are in the service manual.

 

There are no specs for the TCI. Basically the diagnostic is to rule everything else out and then replace the TCI.

 

The pre 90 ignition modules have four functional units in them. So, you can have a failure on one and have the other 3 fire ok. Failed solder joints are a common problem.

[timgray]

Well after nearly 2 hours of swearing and smashing of fingers I got one screw off and used the alternative method of removing the Box. I snapped off the other ear.

 

Carefully opened the box and it looks clean. Connectors to the coils look clean. I am now where I can actually get to everything to test it, which means all the tuperware other than the rear fender has been removed. They did not make getting to the ignition components easy did they. I also discovered that the manual lies about the location of the boost sensor, it's sitting right there next to the TCI.

 

I cant tell but there might be some cold solder joints, when my low beam went out I could not see a failed solder joint but it was there.... I'm going to resolder all the joints tonight and test again tomorrow.

 

Then I'll be calling for some troubleshooting help.. I did score a full set of 83 coils in good shape (needs wires and ends, but the coils look like new) for about $20.00 so if I have a dead coil I'll have a "spare"

 

I really do thank everyone for their help. This is making it easier for me by being able to pick your brains.

 

Side note: if I was 400 miles away there is no way I'd be fixing this problem on the side of the road. amazed that you have to disassemble the whole bike to just be able to look at the parts.

[MiCarl]

amazed that you have to disassemble the whole bike to just be able to look at the parts.

 

That's the major drawback to a 1st gen: They're easy to repair but it takes at least an hour to get through the wrappings.

[timgray]

Well bummer....

 

I re-soldered the joints that looked like they could be bad. reinstalled it and it's still not firing on #3. Resoldering went wierd. I never saw solder boil like that before, and I've been working on electronics for 20 years.

 

Still the same problem with #3 not firing, but #4 is now strong again in spark.

 

So on a whim I swapped the wire plugs from #4 and #3 that drive the coils from the TCI and installed old plugs in the wire ends.

 

the coil for #3 works I see a spark if it's being fired from #4's wire connection. I now have spark on #1,#2,and #4. #3 is dead.

 

does that mean my TCI is dead? does anyone have a spare I can borrow or any ideas to verify this theory or a test procedure to verify this? Heck there are no used ones on ebay right now. That's my luck.

Edited September 11, 2009 by timgray

[MiCarl]

It's probably the TCI but you need to ohm out the pickup coils to rule them out.

 

If the pickup coils check good I'd re-solder every joint in the TCI.

 

Also, seems like you'd be just the guy to do board level repairs on a TCI. (HINT) I've seen posts about fragile glass diodes.........

 

If all else fails you might consider the aftermarket TCI that is being discussed. Seems like a guy like you could have a ball with that.

[timgray]

I'm going to ohm out everything this afternoon. But does anyone have the full tech specs on the 83's ignition needs? Dynatek here in the states makes a ignition module for 4 cyl motorcycle engines that is the same price as the Croatia one with more features and looks like it can use the boost sensor, MSD also makes one as well.

[MiCarl]

I'm going to ohm out everything this afternoon. But does anyone have the full tech specs on the 83's ignition needs? Dynatek here in the states makes a ignition module for 4 cyl motorcycle engines that is the same price as the Croatia one with more features and looks like it can use the boost sensor, MSD also makes one as well.

 

Remember that in line 4 cyls have 2 cylinders at TDC at a time (All crotch rockets I believe). They typically have 2 pickups and 2 coils as opposed to 4 each on our pre-90 V-4s. You could probably use the same work around the Croatia guys did, but you'll have to work it out yourself.

[timgray]

Anyone know what pins on the TCI Ignitor unit are the coils? -- nevermind, I found a pinout. Don is a lifesaver for making this.

http://www.bergall.org/temp/venture/tci/tciplugs.jpg

 

 

I've got all other wires mapped but on the wiring diagram in the manual it's "mystery" 5 wires drawn in with no colors.

 

Coils are fine they all read 3.3 ohms.

 

Pickups read at all 4 positions. 118,113,118,116 ohms. They check out fine as well.

 

Nice to see that the most reliable part on these bikes is the part that fails on me. My luck....

 

I need a new one, THEN I'll tear into the dead one and hopefully figure out a parts list and schematic if possible so that these things can be fixed.

 

This winter I'll be looking for dead TCI's to go through and determine failure points.

Edited September 11, 2009 by timgray

[timgray]

Remember that in line 4 cyls have 2 cylinders at TDC at a time (All crotch rockets I believe). They typically have 2 pickups and 2 coils as opposed to 4 each on our pre-90 V-4s. You could probably use the same work around the Croatia guys did, but you'll have to work it out yourself.

 

Actually the MSD one can even be used for a 4cyl car, it's that configureable. I asked them for more details about sensor inputs, if it can be used to accept the Boost sensor input then it might be very useful.

 

What I do like is the triple spark for every fire and at 40Kv instead of our stock weak 8Kv.