Diagnostic Aids

Water or foreign material in fuel can cause a no-start condition during freezing weather. Engine may start after 5-6 minutes in a heated shop. Problem may not reoccur until vehicle is parked overnight in freezing temperatures. Ensure connections are not contaminated, corroded or damaged.

Low fuel pressure can result in a very lean air/fuel ratio. Fouled or damaged spark plugs will also cause "Engine Cranks But Will Not Run" condition.

Fig 1: Chart A-3 Schematic, Engine Cranks But Will Not Run

Courtesy of GENERAL MOTORS CORP.

Fig 2: Chart A-3 Flow Chart, Engine Cranks But Will Not Run

Courtesy of GENERAL MOTORS CORP.