1988 Tach

[sparky2eh]

Hi, I am looking for some tach help/insight/suggestions, as is everyone here it seems
I have the 302/T5 combo installed with no major problems as I did the search/reading thing and improvised etc etc. Now that it is pretty much finished, and is extremely fun to drive, I want to see if I can use the factory tach.
So is it possible to change the factory tach to correctly/roughly read 8 cylinders in a 1988 that was formerly a 2.3L 4 cylinder?
I used the search and found some info ...... I removed the tach but I do not see any adjustment screws on the back of the tach, well that I can see anyway, and it does not say 8 cylinder anywhere on the circuit board. So any ideas? Thanks.

 

[sparky2eh]

Ok, I think I got it figured out so it reads at least very close to the correct rpms....... so in case anyone is interested or needs this info in the future..... the 88 2.3 tach, well the one in my truck anyway, had 4 terminals labeled Batt, Gnd, Sig and L2 so I figured I needed Batt (battery), Gnd (ground) and Sig (signal) so I removed the nut from the L2 terminal, which I have no idea what it is for unless it is some kind of transistor biasing magic stuff , anyway this effectively removed that connection from the circuit board. I was planning on installing a ground wire on it but for some reason I started the truck first and viola.... 750rpms at idle vice the 1500 it use to show...... it even sounded like about 700-750....... so I left the L2 terminal disconnected and it seems to match engine speed quite well....... yeah me

 

[sparky2eh]

Well apparently I built a really good engine as 6000 rpms is quite normal at 90kms..... so I guess the tach is not linear in scale
Nice try........ so ignore the tach or get an aftermarket one I guess........

 

[Teddyzee]

http://www.rangerpowersports.com/forum/showthread.php?268010-tach-help-1986&highlight=tach
Also, if nothing works, I hear it's fairly straightforward to swap the tach setup form an F150 into your Ranger cluster.

 

[sparky2eh]

Thanks actually read that thread...as well as many others... I am leaning to swapping in a V8 tach..... well as soon as one shows up in the yard
I tried removing the wire from the "L2" terminal, which I assumed was the same as the "cyl" or "8 cyl" mentioned, and grounding it and the tach dies..... maybe the 2.3 litre trucks of the 88 vintage are different... or maybe I have to run new wires to the tach from the coil.... or well when I get bored I will play with it again I am sure...... right now 6000rpms is impressive looking LOL