I recently tuned up my Spider because it was running very rough at low RPMs and hard starting, after the tunup the results are the same. Carb rebuilt about 4000 miles ago. This is a new problem, at 3000 RPM runs great. Any ideas?
When Fiat had to meet emissions laws, that was the end of the line for them…If your Spider is equipped with an RGR valve, try disconnecting, blocking off or otherwise disabling it and see if that helps…