1991 tach problem

[yellow91]

where is my tach filter located on my 1991 vette L98 auto, my tach is way off it idles at 1000 and revs way over 6000. my idle is fine computer or timing light reads 700 rpm.

 

[Eagle85C4]

The filter is attached to the rear of the drivers side head. Follow the wire from the distributor cap labled tech back to it. You can disconnect both sides of the filter and connet those 2 wire to make it work temporarily. You can send it to me for a rebuild. I have a better design for the filter using heavier duty parts then stock and as most of the filters suffer from water damage I seal the filter with hot glue then cover it with RTV to prevent water from entering the can or wires. The cost is a measly 25.00 plus shipping....

FYI do a search for tach filter to hear remarks about my repair. The cost is for parts only labor free for CAC members. PM me for address....

 

[yellow91]

I took a look under the hook to find the filter, but the wire from the cap goes straight into the wire bundle and into the computer. Theres nothing behind the drivers side head but that bundle of wires that goto the computer. how big is the filter, I do see a 1" by 2" black box that may be connected to it , its right under the distributer about 1" pass where the wire enters the bundle of wires that heads to th computer, but it is not connected to the cylinder head.

 

[Eagle85C4]

On my 85 and others it is attached to the rear of the drivers side head between it and the firewall. It is not easy to see or get at. On the distributor cap where the wires attach to the coil on top of the cap, one on the side is labled "TACH"...follow it back and it should lead you to the filter. Here is a pic of what it looks like.