It's gotta be something simple. The facts are that the car spent alot of time sitting, to boot, seeing the images you posted some of that time was outside, with Canadian humidity. Those two facts alone create the perfect issues, corrosion. Check ground connections, battery, motor to chassis etc. Your fuel tank if it wasn't stored full, can create condensation and more corrosion to mix with gas and whatever else is stagnant in the tank. Crap flows through the fuel pump and filter. Check for air leaks in the plastic intakes near the FI. Sitting around is the worst thing for your car, it sucks. It's likely not the fault of the bodyshop unless they deliberately disconnected and reconnected a ground strap somewhere.

http://www.mirafiori.com/faq/fiatFI_may2002.pdf
http://www.hiperformancestore.com/Ljetronic.htm