I've got a sei mpi 1.1 s, it hasn't got a rev counter. I stripped a sporting for parts and got the tachometer just I case, I checked on mine for maybe a plug that was left but no luck, is there a way of making the taco work?

Yes there is. You have to connect 3 cables, one to the ecu, one 12v and a earth

But which pin on the Ecu?

Towsejames said:

.... is there a way of making the taco work?

Click to expand...

Yes, plug it in

There is a connector on the main loom for the tacho connection cable by the N/S door lower hinge https://www.fiatforum.com/cinquecento-seicento/242918-rev-counter-sei-mpi-3.html
Some non tacho equipped MPI cars do have the connector cable (tied up under the middle of the dash).... but some haven't got the cable fitted -in which case James might be able to help you out with that, send him a PM- https://www.fiatforum.com/members/jiminwatford/
For future reference the 'Search this Forum' function on the main page is good for researching problems, there's also a Workshop Manual in the 'Downloads' section (or buy a CD off Ebay for a few quid).