My sister's Punto was misfiring and I diagnosed it as a coil. (If you pulled the plug on the suspect coil, it made no difference to the rattling of the engine). The manual I have for a MK1 punto says that the resistance of the primary winding should be between 0.495 and 0.605 ohms. The suspect coil was 1.7 ohms. 'Aha!' I said and bought a new pattern part coil. The new coil didn't fix it and when I measured the resistance, it was 1.8 ohms.

Have I bought a faulty coil? Should I get a proper fiat one? Can anyone confirm that the info I have on the resistance is correct?

Apparently if the ecu detects too high or too low resistance in a coil, it shuts down those 2 cylinders.

I could be the meter you used. reading low impedances accurately is not something you can do with a cheap meter.

Does yours have the facility to join the leads together and set zero, so that the resistance of the leads is not added to the resistance you are measuring?