Diagnosing Air In Fuel Lines

Tool Required: 1/4" I.D. Clear Plastic hose

1. To check for air in fuel system. Install a 1/4" I.D. clear plastic hose to the fuel return fitting on top of injection pump and connect the other end to the steel return line.

^ The conditions where the driveability problem occurred may need to be reproduced, i.e. vehicle may need to sit overnight to reproduce a hard start cold condition.

2. Start engine and observe the clear return line. Air bubbles will be evident if there is air in fuel system.

3. If air is found. locate source using Section 4 of driveability and emissions service manual.