Tachometer acting weird
Thread Starter
Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
Tachometer acting weird
Hi guys, I had recently fixed a few things in my dash board. I had removed the cluster and reinstalled it, I just noticed this problem. Also the other day I installed an MSD coil. What's happening is if I rev the engine the tach doesn't go passed 2600 RPMs even though you can hear the engine RPMs increasing. But if I slowly take it up passed 2600 RPMs it's fine. Does anyone have any ideas as to what is going on? The previous owner said that the cluster was rebuilt a year or so ago. The car is a 1985 by the way. Thanks for any help.
Team Owner
Joined: Sep 2003
Posts: 25,366
Likes: 2,732
Hi guys, I had recently fixed a few things in my dash board. I had removed the cluster and reinstalled it, I just noticed this problem. Also the other day I installed an MSD coil. What's happening is if I rev the engine the tach doesn't go passed 2600 RPMs even though you can hear the engine RPMs increasing. But if I slowly take it up passed 2600 RPMs it's fine. Does anyone have any ideas as to what is going on? The previous owner said that the cluster was rebuilt a year or so ago. The car is a 1985 by the way. Thanks for any help.
Cost is "nothing" to try!
Thread Starter
Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
Use a scanner and check the RPM's at the ALDL and see what's going on there. You might want to bypass the tach-filter and see if that would correct it. I would guess that the bypass of the tach-filter would be the fix. I've seen MSD notes previously that mention the bypass but I thought that likely only applied to a complete MSD ignition product.
Cost is "nothing" to try!
Cost is "nothing" to try!
Team Owner
Joined: Sep 2003
Posts: 25,366
Likes: 2,732
Follow the white lead and you'll come to the filter. The filter is actually on an '85 the filter and also the wire leads on either end of it. It gets moved around many times during services but you should have no issues putting your hands on it. Original location would be rear of LH cylinder head I believe.
Drifting
Joined: May 2006
Posts: 1,428
Likes: 7
From: Chewelah Wa
It is on the upper bellhousing behind the distributor (the wire comes out of the dist.) underneath the oil pressure sending unit. 'No Bueno' on the fun factor, my wire was broke under the insulation. Took a lonnnngggg time to fix.
Thread Starter
Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
One person here said that he blew out his tach by bypassing the filter, and other people say to buy the MSD tach filter. http://www.thirdgen.org/techboard/af...ilter-msd.html
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Team Owner
Joined: Sep 2003
Posts: 25,366
Likes: 2,732
One person here said that he blew out his tach by bypassing the filter, and other people say to buy the MSD tach filter. http://www.thirdgen.org/techboard/af...ilter-msd.html
Melting Slicks
Joined: Mar 2008
Posts: 2,141
Likes: 76
From: Santa Maria, CA
One person here said that he blew out his tach by bypassing the filter, and other people say to buy the MSD tach filter. http://www.thirdgen.org/techboard/af...ilter-msd.html