Could this be a Tach Filter going bad?
Thread Starter
Le Mans Master
Joined: Apr 2000
Posts: 6,341
Likes: 1
From: Shelton CT
Could this be a Tach Filter going bad?
I notice, that mostly when the car is still cold, the tach lcd every now and then , for a split-second flashes the whole display..
This goes away after about 10-15 minutes, or when the car warms up.
Would this be a tach filter? Also this only started happening, since I spliced into the tach wire to add my analog Tach.
Now the 2nd question is, can I just go out and buy a generic GM tach filter? or is it a special part for our vettes. ('85 in my case).
Thanks..
This goes away after about 10-15 minutes, or when the car warms up.
Would this be a tach filter? Also this only started happening, since I spliced into the tach wire to add my analog Tach.
Now the 2nd question is, can I just go out and buy a generic GM tach filter? or is it a special part for our vettes. ('85 in my case).
Thanks..
Burning Brakes
Joined: Apr 2000
Posts: 980
Likes: 2
From: Chandler AZ
Re: Could this be a Tach Filter going bad? (MrNuke)
I had a similar problem on my 90. I know mine was a needle and yours is digital. Any way it did jump ebvery once in a while when it was warm also but mostly a cold issue. I just had to clean and tighten the ground on the tach filter. If yours is a digital, it may also be in the dash.
[Modified by VAHROOM, 10:16 PM 4/29/2004]
[Modified by VAHROOM, 10:16 PM 4/29/2004]
Le Mans Master
Joined: Jul 2001
Posts: 8,181
Likes: 2
From: Santa Maria, CA
Re: Could this be a Tach Filter going bad? (MrNuke)
The leads off my filter fell out of the thing so I just cut it out and ran it straight. I noted no difference in display. :confused:
I wonder what the thing filters out tho? :confused:
RF frequency?
I wonder what the thing filters out tho? :confused:
RF frequency?
Thread Starter
Le Mans Master
Joined: Apr 2000
Posts: 6,341
Likes: 1
From: Shelton CT
Re: Could this be a Tach Filter going bad? (89 Paul in Cal)
Hmm... Not sure... I think it is supposed to 'align' the tach/rpm signal beacon so the ecm sees a nice and clean signal, not an erratic one that could be affected by voltage/current differences per rpm?
Burning Brakes
Joined: Apr 2000
Posts: 980
Likes: 2
From: Chandler AZ
Re: Could this be a Tach Filter going bad? (89 Paul in Cal)
I wonder what the thing filters out tho??
