Tach does funny things
Thread Starter
Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
Tach does funny things
Yesterday I put my foot into it and was lookin at the tach, first it seemed to get up there slower, and when it did it kind of bounced down as the rpm increased (@ approx. 4500 rpm, man. shifting an a-4 trans).
This is the first time this tach. has acted this way, I do need it to work correctly. I know I could always get an aftermarket, it would be nice if the original worked properly. Any ideas that I can do to fix it is appreciatted, Thanks in advance m7
This is the first time this tach. has acted this way, I do need it to work correctly. I know I could always get an aftermarket, it would be nice if the original worked properly. Any ideas that I can do to fix it is appreciatted, Thanks in advance m7
Thread Starter
Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
Originally Posted by Pete K
Most of the time , the tach filter is the problem.
I had considered this I just wasn't aware that mine had one of those. I seen them for up to 89, so I guess the next question is, does the 90 have one? and what am I looking at as far replacing (haven't looked at my shop manual am at work right now) Mick
Instructor
Joined: Jun 2005
Posts: 193
Likes: 0
From: woodinville washington
your '90 has one, and as far as replacing it...good luck, they are not made anymore, i've been trying to find one for a few months now without luck. Someone else may know how to make one, but i just gave up.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
I broke a wire off of my tach filter a couple of years ago. I plugged the connector that plugged into the output of the tach filter, directly into my distributor, and the tach has worked great (well at least as great as they can) ever since. If you need a tach filter, check this out: http://my.execpc.com/C4/4A/rodney1/corvette/
RACE ON!!!
RACE ON!!!
Thread Starter
Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
Thanks to all for the responses, 
CFI-EFI, that is excellent info, I shot the guy an email regarding one for mine, not that bad price wise. Tommorow I'm going to find mine and see what it looks like. I'm really thinking about tryin your solution, that thing reminds me of the old capacitors in a point distributor. Either way it looks like I might be able to get it going right, which would be
Thanks, Mick
CFI-EFI, that is excellent info, I shot the guy an email regarding one for mine, not that bad price wise. Tommorow I'm going to find mine and see what it looks like. I'm really thinking about tryin your solution, that thing reminds me of the old capacitors in a point distributor. Either way it looks like I might be able to get it going right, which would be
Thanks, Mick
Race Director
Joined: Feb 2004
Posts: 12,517
Likes: 19
On my 87, the tach filter is located on the drivers side, upper, transmission bellhousing bolt. VERY difficult to get to. If an msd ignition is installed, the filter must go. Therfore, you may be able to round up a used one from another forum member. I suspect many are sitting in a junk box in the garage. Hot Rod 90, formely bradvette. Had the same proble on his 90. Maybe he has some good advise. Shoot him a pm.
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