Fuel Quality

Fuel System Diagnosis (Fuel Quality)

Certain driveability problems can be related to fuel quality. The Fuel Related Driveability Problems table lists some of those conditions and which fuel characteristic may be the cause. However, fuel testing is limited. Therefore, all other system checks must be performed (e.g. Powertrain System, Fuel System, Ignition System, Emission System) before fuel quality is diagnosed. If these checks fail to solve the problem, gain information from the customer about when the condition occurs, when and where the fuel was purchased, and which octane level was used. Ask the customer to change fuel brands. If the symptom persists, perform the Fuel System Diagnosis test. If this is not conclusive, drain the tank and refill with a known good quality fuel.