the fuel system is a return system on this car.. So fuel goes down a line from the pump housing, down the car to the throttle body, past the injector to a regulator, and the regulator holds the pressure right across the injector and lets the surplus fuel past down the return line back to the tank, it enters back through the top of the fuel pump housing. It doesn't go through the EVAP system at all.. The EVAP has a vacuum hose that goes to the rear of the throttle body and its controlled via the little valve on the canister which is just an open/close switch controlled via the ecu. The fuel flow and return pipes could very well be a leaking point - there is an access panel under the rear seats in most fiats, been too long for to remember if the mk1 has it but i would bet money it does.. Unlike my suzuki which you have to drop the whole tank off to service anything there. The pipes are quick release type but you unless there is evidence of a leak around the fuel pump housing and the hoses i wouldn't expect its there but no harm pulling them pipes off and having a good look for cracks in the bit they clip onto - i have seen a few cracked/snapped there but usually its really obvious as there is pressure in them pipes when the system primes and engine running.
I have posted a in the mk1 punto guides section a little diagram that shows what every part of the throttle body is and where all the pipes go if you are interested
I have posted a in the mk1 punto guides section a little diagram that shows what every part of the throttle body is and where all the pipes go if you are interested
