Jumpy tach

[the_dingman]

I noticed the other day while doing about 80 on the interstate that my tach was jumping around, moving +/-500RPM. It seems like it's dipping down from the correct RPM, sometimes staying at the lower number for a few seconds.

I'm wondering where the tach connects under the hood. I recently replaced my ignition coil, and think I may have a loose wire.

'87 w/22RE

Thanks guys.

 

[KidVermicious]

Well, since nobody else has answered, I believe the tach wire comes off the coil pack, doesn't it?

 

[the_dingman]

Well, since nobody else has answered, I believe the tach wire comes off the coil pack, doesn't it?

I was thinking it had to come off the igniter or the coil, and the coil only has a positive, negative, and output wire on it.

 

[fourwd1]

Tach connects to the black wire on the ignitor, which IIRC, is the same as the neg wire on the coil.