2000 Fiat Siena

Computer problem
2000 Fiat Siena Front Wheel Drive Manual 7500 miles

Car Type : Fiat siena weekender, 100 1.6 V

Its the brand new original engine(replaced), once engine is heat(after riding) it accelerates automatically or switch off when we press the clutch to change gear. Rpm stays there at around 25000, if you pull the accelerator pedal back most of the time it comes to normal or engine switching off. The idling is not constant at all. Without pressing accelerator the car is not starting most of the time, self motor is also new & original.
I checked with the service person, they said to check electrical wiring, throttle body & ECM.
But the service person shows less interest because of its complexity. Electrical wiring, throttle body can be checked or changed. But how to check the ECM? Is it repairable. What is the best way to check electrical wiring? Could you help me on this?
September 24, 2010.

Start by checking the throttle cable and throttle posion sensor and replace as necassary

Dave H
Jan 23, 2011.