Engine Controls - Tests W/o Codes: Other Mercedes-Benz E-class W210/S210

ENGINE HARD TO START

1. Air in fuel system.
2. Clogged fuel filter.
3. Poor fuel quality.
4. Fuel tank empty or fuel tank vent blocked.
5. Restricted, blocked or leaking fuel injection or supply lines.
6. Incorrect timing or defective fuel injection pump.
7. Low or uneven engine compression.
8. Injection sequence does not correspond with firing order.
9. Restricted or damaged air filter.

ENGINE SURGES AT IDLE

1. Air in fuel system.
2. Fuel tank empty or fuel tank vent blocked.
3. Low idle speed.
4. Incorrect timing or defective fuel injection pump.

ENGINE HAS ROUGH IDLE WHEN WARM

1. Air in fuel system.
2. Poor fuel quality.
3. Low idle speed.
4. Restricted or damaged fuel injector.
5. Injection sequence does not correspond with firing order.
6. Low or uneven engine compression.
7. Incorrect timing or defective fuel injection pump.

ENGINE MISFIRING UNDER LOAD

1. Air in fuel system.
2. Poor fuel quality.
3. Fuel tank empty or fuel tank vent blocked.
4. Clogged or defective fuel filter.
5. Restricted, blocked or leaking fuel injector or supply lines.
6. Incorrect timing or defective fuel injection pump.
7. Restricted or damaged fuel injector.
8. Restricted or damaged air filter.

ENGINE HAS LOW POWER

1. Air in fuel system.
2. Poor fuel quality.
3. Fuel tank empty or fuel tank vent blocked.
4. Fuel control lever not obtaining full throttle.
5. Clogged or defective fuel filter.
6. Restricted, blocked or leaking fuel injection or supply lines.
7. Incorrect timing or defective fuel injection pump.
8. Restricted or damaged fuel injector.
9. Restricted or damaged air filter.
10. Low manifold pressure.
11. Injection sequence does not correspond with firing order.
12. Low or uneven engine compression.

EXCESSIVE FUEL CONSUMPTION

1. Poor fuel quality.
2. Incorrect timing or defective fuel injection pump.
3. Damaged fuel injector.
4. Restricted or damaged air filter.
5. Injection sequence does not correspond with firing order.
6. Improper idle speed.

ENGINE WILL NOT SHUT OFF

1. Restricted, blocked or leaking main vacuum line.
2. Defective main vacuum line check valve.
3. Defective vacuum pump.
4. Defective injection pump stop vacuum unit.

WHITE OR BLUE EXHAUST SMOKE

1. Air in fuel system.
2. Poor fuel quality.
3. Clogged or defective fuel filter.
4. Restricted or blocked fuel injection or supply lines.
5. Incorrect timing or defective fuel injection pump.

INCORRECT IDLE SPEED

1. Improper idle speed adjustment.
2. Defective fuel injection pump.

ENGINE SPEED WILL NOT INCREASE

1. Air in fuel system.
2. Poor fuel quality.
3. Fuel tank empty or fuel tank vent blocked.
4. Fuel control lever not obtaining full throttle.
5. Clogged or defective fuel filter.
6. Restricted, blocked or leaking fuel injection pump.
7. Incorrect timing or defective fuel injection pump.
8. Low or uneven engine compression.