MBE 4000 DDEC VI Troubleshooting – Section 9.8 Improper Grade of Fuel

Section 9.8
Improper Grade of Fuel

To determine if an improper grade of fuel is causing excessive black or gray smoke, perform the following:‪

1. Acquire a fuel sample from the vehicle fuel tank(s).
2. Submit fuel sample for an ASTM test analysis.
   1. If the fuel meets specifications, check for a faulty EGR valve; refer to "9.9 Faulty EGR Valve" .
   2. If the fuel did not meet specifications, resolve improper grade of fuel;refer to "9.8.1 Improper Grade of Fuel Resolution" and Detroit Diesel publication Lubricating Oil, Fuel, and Filters (7SE270).

Section 9.8.1
Improper Grade of Fuel Resolution

Perform the following steps to resolve the improper grade of fuel:‪

1. Drain the fuel tanks, refer to OEM guidelines, and dispose of fuel properly.
2. Refill the fuel tanks with new fuel having a cetane number greater than 45 and cetane index greater than 40.
3. Verify fuel resolution eliminated the excessive exhaust smoke condition; refer to "9.8.1.1 Test the Engine with New Fuel" .

Section 9.8.1.1
Test the Engine with New Fuel

Perform the following steps to determine if the fuel refill resolved the excessive exhaust smoke condition:‪

PERSONAL INJURY ‪
To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.‪

1. Start and run the engine.
2. Run the engine at idle under no-load conditions for approximately five minutes, allowing the engine coolant to reach normal operating range, approximately 88-96°C (190-205°F).
3. Visually inspect exhaust for excessive smoke.
   1. If the engine smoke emission appears normal, no further troubleshooting is required. Shut down the engine.
   2. If the engine exhaust smoke is excessively black or gray, shut down the engine. Check the EGR valve; refer to "9.9 Faulty EGR Valve" .