tach filter help please
Thread Starter
Burning Brakes
Joined: Jan 2004
Posts: 791
Likes: 1
From: lincoln ri
tach filter help please
I have searched postings relentlessly for a location and how to access the tachometer filter on my 1988. I am getting a lot of movement on the graph at highway speeds. This has happened ever since I had replaced the head gaskets. I have been checking for loose wires, etc., but have not found any. Some posts have said it's bolted to the top of the bell housing. Is this accessible without removing everything I just re-installed??? I have noted that there are several different locations described in various posts. I have tried to follow the "white wire" coming out of the firewall, to no avail. Any suggestions would be great!!
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 41
From: Baltimore, MD USA
One end of the wire goes to the driver side of the distributor cap.
The other end goes thru the firewall into the interior.
The tach filter itself should be bolted to the 3rd bell housing bolt
on the Driver side. There is a wiring harness that may also be
attached to the same bolt making it hard to see the tach filter.
If that bellhousing bolt needs to be removed most people
use 2 to 3 ft of 1/2 drive extensions and a universal to get to it
from under the vehicle.
Some people after replacng a tach filter, change the location where
they bolt the tach filter to make it easier to replace in the future.
The tach filter bracket is ground for the filter so it needs to be
grounded. Doesn't explain your problem because it doesn't need
to be unbolted to remove the heads.
The other end goes thru the firewall into the interior.
The tach filter itself should be bolted to the 3rd bell housing bolt
on the Driver side. There is a wiring harness that may also be
attached to the same bolt making it hard to see the tach filter.
If that bellhousing bolt needs to be removed most people
use 2 to 3 ft of 1/2 drive extensions and a universal to get to it
from under the vehicle.
Some people after replacng a tach filter, change the location where
they bolt the tach filter to make it easier to replace in the future.
The tach filter bracket is ground for the filter so it needs to be
grounded. Doesn't explain your problem because it doesn't need
to be unbolted to remove the heads.
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
Thread Starter
Burning Brakes
Joined: Jan 2004
Posts: 791
Likes: 1
From: lincoln ri
Thanks for the tips; I'm thinking it may have been damaged during the head gasket work, etc. Maybe not, but after that work was done was when I noticed the "jumpy tach".If I can find the "brown" wire, I'm just going to cut each wire and splice a new filter in, and bolt it somewhere for a little more convenient ground location. I have read that some just delete the filter.
