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Discussion Starter · #1 ·
OK fellas'
Back to tachometer problems again.
My tach only starts to work when I get to 50mph. At that time, it goes right up to 4500rpm and increases to 5000rpm at 60mph. When I get below 45mph, it drops to 0. Has anyone run into this problem before, or have a suggestion????? (Wife's getting upset with me coming into the garage at 50)

Secondly. Spark plug gap????????????
Book said 8MM to 9MM. Not having gauges in MM, I converted that to .020/ .022. Does that seem about right???

As usual, any suggestions is appreciated...

Joe
 

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The easy one first...

1.0 mm = 0.039 inch, so just multiply milimeters by 0.04 for a good approximation.

8 to 9 mm then is .032" to .036"


The tacho...

Well, we've been over a bunch of really odd possibilities on this sort of problem before.

The first thing I'd suggest is swapping the #1 and #3 ignition coils.

If the problem goes away, you've got a bad ignition coil or bad connections.

If the problem stays, remove the tach and clean the contacts and wire ends that screw into the back.

Give the above a try and let us know how it works.

Jim
 

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Discussion Starter · #3 ·
Thanks Jim. Nothing ventured, nothing gained.

And thanks also for getting me straight on my figures.
I would have been right if I was going to MM.
( Don't know if I'm coming or going most of the time)

Joe :)

[ This message was edited by: Adventure96 on 2006-11-10 19:16 ]
 

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Discussion Starter · #4 ·
Jim.

I tried what you suggested to no avail, but it was certainly worth a try. I'm hoping that a shop here in Atlanta may be able to check the tach out or maybe rebuild if it is in fact the tach, not the igniter.
Thanks for the quick come back. I'll try to keep you posted on the out-come.
(These maint. books that I bought don't tell you a thing about tachs. almost like they don't exist. Triumph book included.)


[ This message was edited by: Adventure96 on 2006-11-14 16:42 ]
 

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Hey Adventure96,
I see you're in fayetteville. I have a spare tach from a 97 tbird that is a match for yours. I swapped it out because it was jittery. It would probably work good for troubleshooting at least. I live in Dawsonville and come to Newnan often. I'll give it to you, if you want it. let me know
 

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Discussion Starter · #6 ·
HeyMan. That would be absolutely fantastic. At the present time, I don't know if it's the tach or the igniter. If you let me know when you'll be coming down this way, I'll sure enough meet up with you.
If you'd like, I'll send you my phone number, via pm. What ever is convenient with you. :-D

Joe

I'll even buy ya a biscuit

[ This message was edited by: Adventure96 on 2006-11-14 16:39 ]
 

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I'm hoping that a shop here in Atlanta may be able to check the tach out or maybe rebuild if it is in fact the tach, not the igniter.
Don't hold out a lot of hope for a repair since it's an electronic tach and considered a 'throw-away.'

If the shop can't fix it, e-mail me.

It might be possible to add an input filter to the tach and stabilize the behavior, but I'd need a bad tach to experiment on.

Jim
 

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Discussion Starter · #9 ·
Dan. Sent two more messages this am. but just in case.
(
(
Joe

[ This message was edited by: Adventure96 on 2006-11-16 17:51 ]
 

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It might be possible to add an input filter to the tach and stabilize the behavior, but I'd need a bad tach to experiment on.

Jim
I still have the spare I was swapping parts with. The bezel is currently off so easy access to the circuit board. I kind of gave up after I couldn't locate the tach driver IC. Finding a X-ref on an obscure chip like that is a pain. So I just put up with my jumpy tach. I just don't know if these tachs get damaged or if there is really something flaky in the igniter/coils that causes the weird behavior.
Anyway, if you want one to experiment with I can send it to you. Hopefully you can learn something that will benefit us all. PM me if you want it.

Stan
 
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