91 Tach Issues (1 Viewer)

[justinf307]

I just finished up swapping a good 3FE into my 91. It runs and starts great, but the tach. is not working. Since it never ran when I bought it I am unsure if the tach worked before the swap. I have a code 12 for no rpm signal.

I have read that the igniter signal can be found at the diagnosis port, but I'm unsure how to "check" the signal. I would assume I cant just stick a multi-meter in that pin?

Is it possible that the igniter is just not sending the tach signal, but functioning otherwise? Since it seems to run well, everything must be functioning from the pick-ups to the igniter.

Thanks, for the help, been searching for hours on this one.
Justin

 

[Alleycats]

Maybe something like this in the right pin?

LCD Automotive Multimeter with Tachometer Kit

 

[justinf307]

Thanks! I'll have to go to town and get one and try it out.

 

[justinf307]

For future reference to anyone with similar issues...
I recently purchased a couple cheap igniters from a member here just to try in case for some reason that might be the issue. When I pulled the old one it appeared to be an aftermarket part. Turn out after talking to the previous owner he remembered the tach went out around the same time they had a bunch of ignition work done. It would seem that the aftermarket piece does not have the sender for the tach, they are definitely shaped differently anyways.
Anyways hope this helps someone in the future.