Engine Cranks, But Will Not Run

Diagnostic Chart.:

DESCRIPTION

SATURN has two computerized fuel control systems, throttle body injection (TBI) and multiport fuel injection (MFI). Spark is delivered from a distributorless ignition system (DIS). In order to diagnose this system, battery voltage must be above 11 volts. Cranking speed of the starter must be normal and fuel quality should be checked.

PARAMETERS

^ No start due to no spark or RPM signal.

^ No start due to low or no fuel pressure.

DIAGNOSTIC AIDS

^ Water in the fuel can cause a no start during cold weather starts.

^ A CTS sensor reading incorrectly can cause a no start or a hard start. This may be due to over fueling or under fueling.

^ CTS may be compared to ATS temperature with a scan tool if engine has cooled overnight at ambient temperature. They should be within four degrees of each other with ignition ON and key OFF.

^ A shorted injector will cause a no start condition on both TBI and MFI.