Fuel System Checks

Check the Evaporative Emission (EVAP) control system. See EVAPORATIVE EMISSION CONTROL SYSTEM DIAGNOSIS under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM in SYSTEM & COMPONENT TESTING - 1.8L VIBE article.
Check the fuel injectors for leaking. See FUEL INJECTOR BALANCE TEST WITH SPECIAL TOOL under FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - 1.8L VIBE article.