Ok, after installing a complete MSD system my tachometer is acting funky. I read through the MSD literature, it says there is an inline filter that must be removed for the tach to function properly. Anyone know what it is, where it is, what it looks like? Thanks.

 

Not all third gens have a tach filter, but if you do have one, it will be mounted to the fire wall, behind the distributor. It is a appprox 1/2" diameter x 1.5" long cylinder with two wires attached to it. Disconnect the tach input (white wire that goes up into the harness next to the large pink (ignition power) wire) from the distributor module & connect the tach output of the MSD box directly to it.

Tim

 

I wonder if this is my problem. My MSD equip is making my tach do the same thing

 

Hey TIM, do i need to purchase anything else from MSD to do this?

 

I believe MSD sells a tach filter, but I've never had to use one when driving the factory tach on an '84 & a '92 with the tach output from a 6AL (spade terminal on the side of the box).

Tim

 

I am running a MSD universal boost timing master on a stock HEI system and the tach jumps all over at idle.

With the Jacob's system on line the tach is fine.

Why is the BTM doing this on the stock system?

Do I need the MSD filter?

Thanks.

 

My Tach Is Funked up too. All I have Is an Accel Super Coil which was installed when my new engine was dropped in an the tach hasn't worked right since. Is this filter in the same location on a 1991 5.7L Z?
~Jack~