To determine if the fuel pump is causing excessive white smoke, perform the following steps:
1. Insert a piece of wire through the fuel pump flange drain hole; see Figure 10-1.
2. Crank the engine momentarily and feel for wire vibration.
[a] If the wire did not vibrate; refer to section 10.2.1.
[b] If the wire did vibrate, check for aerated fuel; refer to section 10.3.
10.2.1
Drive Hubs and Coupling Replacement
Perform the following for drive hubs or coupling replacement:
1. Replace the drive hubs or coupling; refer to appropriate service manual, fuel system chapter.
2. Verify the drive hubs and coupling replacement; refer to section 10.2.1.1.
10.2.1.1
Engine Test with Replaced Drive Hubs or Replaced Coupling
Perform the following to determine if replaced drive hubs and coupling resolved excessive white
smoke:
1. Start and run the engine.
2. Run the engine at idle with a no-load for approximately 5 minutes, allowing the engine
coolant to reach normal operating range.
3. Visually inspect exhaust for excessive white smoke.
[a] If the engine exhaust emission appears normal, no further troubleshooting is required.
Shut down the engine.
[b] If the engine exhaust emission is excessively white, shut down the engine. Check
for aerated fuel; refer to section 10.3.
