Engine Cold

Perform the following in order:

• Check IAC valve and IAC air regulator. See SYSTEM/COMPONENT TESTS article.
• Perform power balance test.
• Check fuel injector operation. See SYSTEM/COMPONENT TESTS article.
• Check ignition spark.
• Check condition of spark plugs.
• Check fuel pressure. See BASIC TESTING article.
• Inspect ECM harness connector for damaged pins or poor connection.
• Check ECM power supply and ground.
• Replace ECM with known good unit.