-73 tach problem
Thread Starter
Burning Brakes
Joined: Mar 2004
Posts: 816
Likes: 1
From: Finland
-73 tach problem
symptoms are:
Some times the tach has done so that it stays around 1500rpm and does not move at all...usually it after 5-10 miles starts waking up a bit so that if I rev the engine 3500rpm it slowly follows to 2000rpm and if I idle at 650rpm it slowly drops to 1000 and then later suddenly start working like no problem...sometimes when i shut the engine of the needle still points at 700rpm
Tried to check the cable from distributor end - nothing looked loose there, but the other end I could not reach even spending some time laying on the floor......is the cable loose from one or the other end or is the tach itself starting to fail...
But basically arent those syptoms more saying that the tach is going to break? Is it possible to rebuild the tach myself or should i just order a new from zip 270$ or ecklers 290$ ?
Some times the tach has done so that it stays around 1500rpm and does not move at all...usually it after 5-10 miles starts waking up a bit so that if I rev the engine 3500rpm it slowly follows to 2000rpm and if I idle at 650rpm it slowly drops to 1000 and then later suddenly start working like no problem...sometimes when i shut the engine of the needle still points at 700rpm
Tried to check the cable from distributor end - nothing looked loose there, but the other end I could not reach even spending some time laying on the floor......is the cable loose from one or the other end or is the tach itself starting to fail...
But basically arent those syptoms more saying that the tach is going to break? Is it possible to rebuild the tach myself or should i just order a new from zip 270$ or ecklers 290$ ?
Last edited by Vesa; Sep 7, 2005 at 07:27 AM.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I would try to remove the cable first. The grease inside sometimes gets real sticky and hard. Pull the cable out and clean the cable and then put on a light grease. Slide it back in and see if that helps. I know that is not easy but it is free to try. The tach can be rebuilt with a new head or replaced if the cable is OK. Also check both ends to see tha t they are not rounded off.
Thread Starter
Burning Brakes
Joined: Mar 2004
Posts: 816
Likes: 1
From: Finland
Originally Posted by Gordonm
I would try to remove the cable first. The grease inside sometimes gets real sticky and hard. Pull the cable out and clean the cable and then put on a light grease. Slide it back in and see if that helps. I know that is not easy but it is free to try. The tach can be rebuilt with a new head or replaced if the cable is OK. Also check both ends to see tha t they are not rounded off.
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 180
From: S.W. Ohio. . . . . . NRA Life Member
Originally Posted by Gordonm
...The tach can be rebuilt with a new head or replaced if the cable is OK. Also check both ends to see tha t they are not rounded off.
the tach can also be converted over to electronic use... using your original dial face and pointer. A total stealth conversion.
email me for details:
tim-yvonne@juno.com
Le Mans Master
Joined: Sep 2003
Posts: 8,812
Likes: 2,029
From: eastern NC
Originally Posted by Gordonm
I would try to remove the cable first. The grease inside sometimes gets real sticky and hard. ....
But before you do this, and since you do have a new MSD distributor, disconnect the tach cable from the distributor and spin the cable to see if you get a reaction on the tachometer. You can use a reversable drill also to see if it moves smoothly or intermittently. If the tach responds to this as you've described above, you can easily eliminate the distributor as the problem and dive into the back of the dashboard... The cable must be removed from the tachometer end, so you're gonna have to get dirty...
Good luck... and let us know what you find
GUSTO
Thread Starter
Burning Brakes
Joined: Mar 2004
Posts: 816
Likes: 1
From: Finland
I have removed the tach from the car and after trying to learn how it works (and after tearing in into bits and pieces) I found that the main bearing has too much end play - so there is only small tuning possible to do which might help for a short while but anyway it is at the end of the lifecycle now...
And the cable is all ok.
So I will place a order to some shop and get a new unit...
And the cable is all ok.
So I will place a order to some shop and get a new unit...
Last edited by Vesa; Sep 23, 2005 at 04:31 PM.
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