System Diagnosis - Fuel System

Diagnostic Chart:

DIAGNOSIS PROCEDURE

Always start with the Powertrain OBD System Check. Testing and Inspection

The Powertrain OBD System Check table will identify other tables for specific checks, such as:

^ Fuel System Pressure Test System Diagnosis - Fuel System Pressure Test

^ Fuel Injector Balance Test Fuel Injector Balance Test

^ Fuel Inj Coil Test - ECT Between 10-35 Degrees C Fuel Injector Coil Test - ECT Temp Between 10-35 Deg C

^ Fuel Inj Coil Test - ECT Outside 10-35 Degrees C Fuel Injector Coil Test - ECT Temp Outside 10-35 Deg C

^ Idle Speed Control Check Idle Speed Control Check

DIAGNOSTIC AIDS

If there is no fuel pressure, check all component and circuit grounds.


FUEL SYSTEM DEPOSITS

Fuel system deposits can cause various driveability problems. Deposits usually occur during hot soaks after key Off. Poor fuel quality or driving patterns such as short trips followed by long cool down periods can cause injector deposits. This occurs when the fuel remaining in the injector tip evaporates and leaves deposits. Leaking injectors can increase injector deposits. Deposits on fuel injectors affect their spray pattern, which in turn could cause reduced power, unstable idle, hard starts and poor fuel economy.