Routine 204-Rough Idle

DIAGNOSTIC ROUTINE 204-ROUGH IDLE

System & Component(s)	Reference
BY-PASS AIR CONTROL BPA Valve (1.8L) ISC-BPA Valve (All Others)	Check timing and idle speed. See ADJUSTMENTS article.
IGNITION Scope engine for: Spark Plugs, Coil, Module, Secondary Wires, Distributor Cap and Rotor Ignition Timing	See BASIC TESTING article.
FUEL DELIVERY Pump Pump Relay Pressure Regulator Injectors Fuel Rail	Perform fuel pressure test. See I - SYS/COMP TESTS article.
EEC Quick Test	See TESTS W/CODES article.
EGR (2.2L) Valve Solenoids Vacuum Hoses	See I - SYS/COMP TESTS article.
INLET AIR CONTROL Electrical & Vacuum Connect. Air Cleaner & Duct Base Idle Throttle Plates & Linkage VAF Meter, Wire Connections	Perform a visual inspection.
PCV Valve	Inspect PCV valve.
TURBOCHARGER Bearings, Compressor, Turbine Housing	Check turbocharger wastegate. See I - SYS/COMP TESTS article.
BASIC ENGINE Compression Camshaft & Valve Train Timing Belt	Check engine mechanical condition.