Tach Issue with MSD setup

[vamperism]

Hey Everyone,

I just recently installed the MSD 6A and Blaster 2 coil and used the 3055 NPN Transistor and 1K Ohm resistor setup. Now of course the Tach doesn't function past 4000rpm. Has anyone found a successful way to fix this? I've searched but no seems to have posted a solution but yet there are still MX-3s that have had this fixed. Do I need to get a MSD tach adaptor and if so does it get it's source from the MSD box or the Transistor?

[mazdubber]

I don't know if this is even possible, but I wonder if theres a way to wire the stock tach to the coil when using the msd. Any thoughts??? Just a shot in the dark since I'm not sure how it's wired in the first place on mx3's.

[Gro Harlem]

Hrmm...what kind of 1k ohm resistor are you using? i think ur supposed tou se the 1 amp versions, something about the 1/2 amp ones not working right.

[ma24691]

Yeah, same thing happened to me... you have to buy a tach adapter from MSD. There's two or three different part #s, so ask for the one made for a 1993+ Probe V6. It's solid red and shaped somewhat like the profile of a bell. It's really easy to install.

[vamperism]

Originally posted by Gro Harlem:
Hrmm...what kind of 1k ohm resistor are you using? i think ur supposed tou se the 1 amp versions, something about the 1/2 amp ones not working right.

Do you mean 1/2 Watt. Yes I used a 1K Ohm 1/2 Watt Resistor. That's very strange because the Wattage rating just affects it's current capacity. It doesn't change the resistance value. I've heard that a 1/4 Watt or higher was suggested.

[vamperism]

Originally posted by ma24691:
...you have to buy a tach adapter from MSD... It's really easy to install.

Did you run the Tach Adaptor off the MSD Box or the center transistor lead?

[wyldside]

Originally posted by vamperism:

Originally posted by ma24691:
...you have to buy a tach adapter from MSD... It's really easy to install.

Did you run the Tach Adaptor off the MSD Box or the center transistor lead?

Try and run it off of the MSD Box Tachometer Terminal. That should do the trick.

[ma24691]

Originally posted by vamperism:

Originally posted by ma24691:
...you have to buy a tach adapter from MSD... It's really easy to install.

Did you run the Tach Adaptor off the MSD Box or the center transistor lead?

The Adaptor has a red wire and a white one.
You'll have to splice in to the skinny red wire and skinny white wire from the MSD box.
So, from the MSD Box:
Skinny red wire splits 2 ways to:
1)red wire on adapter
2)new wire that will lead towards distributor
according to Jeff Abrams' site.
Skinny white wire splits 2 ways to:
1)white wire on adapter
2)the other new wire that leads towards
distributor according to Jeff Abrams' site.
Hope that helps. Sorry for the delay.

[chertel]

Before my ze swap the tach worked without a tach adapter? all we did was run the stock tach wire to the tach signal wire on the msd box. Now that the ze is in it doesnt work anymore? I am just did the disty mod and added an external coil without hei and a digital msd box.