Fiat Punto wont start no fuel at injectors

bin told srs inertia swich was in there got new 1 from fiat 300 pound then some 1 said ecu but fiat wont 900pound for carnt find the inertia switch any were tried indercator sequance R.L.R.L BUT DIDNT WORK every thing else work bar fuel to injectors its fiat grande punto 59 plate ecu been tested all ok.it all down to inertia any help please.or does any body know phone no to fiat car been in my local fiat dealer 1 week then italian specialist 2weeks still no fixed suspect ecu but its lot money to spend if its not that.does new srs have to be programed to car.the inertia has to be electronic.but were is it no car have car manual but it says driver side kick plate but not there