I have no experience on tachos from Capris, but I do know that in the Sierra some tachos don't like the signal from the EDIS module, as they are designed to work from the negative connection on the coil. Other Sierra tachos actually do work correctly with the EDIS, but I don't know what the difference is between them. A lot of BOA conversions use the original Granada tacho for that reason. I was lucky and the Sierra tacho in my car does work correctly with the BOA.