I have never opened the hood on a FIAT, that said most EFI equipped vehicles of all brands use a system by or similar to Bosch, in which a computer senses load using a throttle position sensor, a Mass airflow (MAF) sensor or a manifold absolute pressure sensor MAP, and an Oxygen sensor in the exhaust. I would check the throttle position sensor(TPS) first, especially if the engine idles normally, but refuses to accept throttle input. The TPS is nothing more than a potentiometer wired as a variable voltage divider. If the engine refuses to idle check the fuel pressure first. If equipped with MAP sensor pull the vacuum hose loose which normally would flood the engine out with too much fuel, if it runs then you are likely are on the right track. Engine runs, but poorly, here is a quick check for the MAF sensor, @ 1500 RPM or more gently tap on the MAF sensor, and if it causes it to miss, buy new.
Joseppie, November 2008
