hi...io got a punto75elx...with some idle problems(high idle speed) and very high fuel consumption..took it to the fiat delaer in my place he claimed that the IAC valve is not working fine and should be replaced and it's the cause of this high fuel consumption...does the IAC valve has anything to do with the fuel consumption??? or there are 2 separate problems that i should look for?...and how much does the IAC valve cost anyway...i dont trust my fiat delaer anymore after he charged me 25€ for a puff of WD-40 in my carburetor ...i would appreciate your help...thank u

A faulty IAC valve could cause an overly high idle which would worsen your gas mileage since the motor is working faster.
I've got the newer Punto and I cleaned out the IAC with some appropriate spray cleaner when I changed my plugs. The result was I had erratic idling for about 3 weeks and then it went away. I freaked out when this happened and priced out a new IAC. In the newer Punto you have to replace the whole throttle body as the IAC is fitted into the TB. Hopefully you won't have to do this.