If you're dealing with issues with a Stanadyne DB2 mechanical pump, this guide will help you diagnose and potentially resolve common problems. Let's dive into some typical issues and their possible solutions.

When you see white smoke during a cold start, it usually indicates fuel in the cylinders. The problem likely lies with cylinder heat, compression, or timing. Here's what to check:

• Glow plug operation

• Engine compression

• Injection pump to engine timing

• Fuel quality

• Cranking speed (should be at least 100 RPM)

No smoke generally means insufficient or no fuel is entering the cylinder. Check these areas:

• Cranking speed (180-200 RPM if hot, minimum 100 RPM if cold)

• Shut-off solenoid connection

• Fuel supply to the injection pump

• Potential air locks in newly installed pumps

Surging can be caused by fuel supply problems or mechanical issues within the injection pump. Look for:

• Air in the fuel supply system

• Worn or sticking governor components in the injection pump

• Stuck cold advance solenoid

This issue is typically caused by a drain-back problem in the fuel supply system or low idle speed. Investigate:

• Idle speed settings

• External fuel leaks

• Fuel filter check valve (especially on 7.3L engines)

• Return fitting on the injection pump

Often related to low lubricity fuels or vehicles that have been sitting unused. Consider:

• Idle RPM settings

• Fuel lubricity (try using a fuel additive)

• Sticking metering valve in the injection pump

White smoke with a fuel smell indicates incomplete combustion. Check:

• Pump to engine timing

• Fuel quality and supply

• Engine compression

• Injector condition

• Injection pump wear

Caused by excessive fuel or lack of airflow. Investigate:

• Air filter condition

• Pump to engine timing

• Turbocharger performance (if applicable)

• Injector and injection pump wear

• EGR system (on some 6.2L and 6.5L engines)

Try to isolate the problem to a specific cylinder. If not possible, consider:

• Engine balance components (flywheel, flex plate, vibration dampener)

• Motor Mounts

• Idle speed settings

• Injection pump condition

Check these areas:

• Full throttle travel to the injection pump

• Pump to engine timing

• Turbocharger performance (if applicable)

• Fuel supply to the injection pump

• Injector condition

• Injection pump wear

• EGR system (on some 6.2L and 6.5L engines)

Often related to fuel supply issues. Investigate:

• Fuel filter condition

• Fuel supply pressure and aeration

• Restrictions in the fuel system

• Fuel supply/lift pump condition