 Tach Bounce |
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| 914Bryan |
 Oct 14 2011, 05:54 PM
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#1
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Member  Group: Members Posts: 190 Joined: 6-June 11 From: Orange County Member No.: 13,162 Region Association: Southern California  |
What can I do about a bouncing tach? When I shift, the needle wildly bounces around until the rpm settles in a gear. Then it either climbs or drops depending on acceleration or decelaration. Any ideas? (IMG:style_emoticons/default/confused24.gif)
74 2.0, stock fi and dizzy/coil |
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| VaccaRabite |
Oct 16 2011, 10:41 AM
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En Garde! Group: Admin Posts: 13,752 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region 
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I don't suppose you could point out the cap that you added for those of us that are electronically challenged?
Zach |
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| Bartlett 914 |
Oct 16 2011, 02:38 PM
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#3
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Advanced Member Group: Members Posts: 2,218 Joined: 30-August 05 From: South Elgin IL Member No.: 4,707 Region Association: Upper MidWest |
QUOTE(Vacca Rabite @ Oct 16 2011, 11:41 AM)  I don't suppose you could point out the cap that you added for those of us that are electronically challenged? Zach My Tach jumps also. I don't remember which cap can be changed. I did change mine (forgot which one) it didn't help. I think the tach needs mechanical dampening. Probably something like a special grease at the pivot point. Here is how I fixed my tach problem. Attached image(s) 
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| Spoke |
Oct 16 2011, 07:05 PM
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#4
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Jerry Group: Members Posts: 7,185 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None
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QUOTE(Bartlett 914 @ Oct 16 2011, 04:38 PM) My Tach jumps also. I don't remember which cap can be changed. I did change mine (forgot which one) it didn't help. I think the tach needs mechanical dampening. Probably something like a special grease at the pivot point. Here is how I fixed my tach problem. The capacitor placed directly across the winding of the needle will settle the tach. I used 3300uF and it was too much. My guess is you used too little capacitance or didn't put it directly across the armature of the needle. Once you put a 2200uF cap across the winding, you will see new-age tach operation without the bouncing of the 1970's era tachometer. |
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Posts in this topic
914Bryan Tach Bounce Oct 14 2011, 05:54 PM
Dave_Darling If your car still has ignition points, check them ... Oct 14 2011, 06:22 PM Valy
What can I do about a bouncing tach? When I shift... Oct 14 2011, 06:23 PM 914Bryan I was thinking points too..Side note, I was thinki... Oct 14 2011, 07:08 PM Vacca Rabite If you are running Djet, you need to keep the stoc... Oct 14 2011, 07:50 PM avidfanjpl Get a pertronix for that car. I only keep points a... Oct 14 2011, 11:47 PM Valy Just for reference, this is what your bad points/c... Oct 15 2011, 02:07 AM 914Bryan Awesome info guys! Thanks! Oct 15 2011, 05:42 PM Tom Valy,
That is some bad switch bounce! The... Oct 15 2011, 07:40 PM michael7810 My tach does the same thing. I have a new distrib... Oct 15 2011, 08:09 PM
mgphoto
My tach does the same thing. I have a new distri... Oct 17 2011, 10:59 AM 914Bryan Sooo maybe an Autometer monster tach instead of th... Oct 15 2011, 08:26 PM Spoke There's 2 basic reasons the tach bounces:
1) ... Oct 16 2011, 10:20 AM Valy
My dear friend,
you solved a symptom, not the... Oct 16 2011, 10:34 PM Spoke
My dear friend,
you solved a symptom, not th... Oct 17 2011, 07:02 AM Valy
[quote name='Valy' post='1556077' date='Oct 17 20... Oct 18 2011, 07:26 PM Spoke
The problem is that the bouncing fools the tach t... Oct 19 2011, 04:40 AM Spoke
I don't suppose you could point out the cap t... Oct 16 2011, 07:01 PM 9146986 Sometimes just putting a clean piece of thin cardb... Oct 17 2011, 10:46 AM larss I had about the same symptoms on my tach, the need... Oct 17 2011, 11:23 AM |
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