Tachometers

[dan-cj7]

I'm building a stroker from a 93 YJ engine and am installing it into a 84 CJ7. From what I'm told the tachometer from the CJ won't work with the newer engine. Is there a module of some kind on the market that will convert the signal to be compatable with my CJ7 tach? I'm trying to keep my restoration as original as possible (apart from the engine of course) and I'm not keen on the aftermarket tacks as I've heard they are not as good as the original equipment.

Thank,
Dan.

[martin809]

You can google YJ to CJ dash conversion. There are a few out there that have done this.
I found this one and about half way down it talks about the tach

http://www.jeepforum.com/forum/f12/yj-c ... es-634392/



The pics didn't show up for me

[doublins]

I had to buy a tach adapter to be able to hook up the tach signal to my piggyback ECU on my TJ- I imagine you´ll need to do something similar for your older tach-

Although my TJ is distributed, there is no tach ¨signal¨ on the TJ it uses a coil driver and the PCM ¨calculates¨ the rpm signal which is sent to the dash on the common bus, as data- not as an analog signal that most normal tachs are expecting- the MSD adapter I purchased hooks up inline with the positive wire ahead of the coil, senses the coil firing, and produces the appropriate standard square wave tach signal that most tachs want to read.

I had tried to piggyback off of my #1 injector for awhile to feed the tach, because it too is a square wave, but it only produced accurate results from about 1500rpm to redline, anything below that and it would jump all over the place-

There are a couple of different tach adapters out there, I used an MSD Ignition 8913 Distributorless Tachometer Driver http://www.amazon.com/dp/B000630D80/ref ... s_sce_dp_1 Just figure out what sort of signal your tach is expecting, and buy accordingly.

-Chris