95' OBD II Tach Signal

I am building a Mutant, Half XJ, half toyota.

I would like to run the factory 80 toyota tach.

So I am wondering any info any of you may have regarding the factory tach signal from the jeep computer. Wire color, signal timing, anything.

Thanks in advance!
XJRubicon

The wire is gray with a light blue stripe and goes into pin 43 of the pcm.