The aftermarket rev counter already fitted to my XR2i only reads half the revs on the dash rev counter. I have checked that the signal wire is connected correctly behind the dash and that the rev counter is switched to 4 cylinder. Any ideas why?



Need help before I destroy car!!!

 

presumably this is a EFI XR2i?
It uses wasted spark twin coil ignition setup - the tacho connection is from one of the coils, so only sees half as many sparks as a conventional 4-cyl distributor system.
Can you set the tacho to 2-cylinder?

 

Unfortunately not. Would connecting the after market tacho signal wire to both coils work? I was thinking perhaps in parallel.

Thanks
Warren

 

you can't join the two coil connections together, or the ignition won't work!!
Possibly if you connected two diodes from the coil connections and then joined to the tacho..? kinda thinking aloud here..