You dont mention ecu stored fault codes,did'nt they run a diagnostic test?Without test codes you/they are guessing,expensive way to fix a fault.That said I'd suspect the temp sensor.they are known to rot but still work within limits.Basically it puts the "choke" on every time the engine starts.and as this engine does'nt have a choke as such,it means it runs rich,hence fuel smell.But only way to be sure is to code read it.
caine
August 2008