What does a sudden decrease in engine power accompanied by black exhaust smoke signify?
Answer and explanation
Correct answer: B. Fuel-rich mixture combustion due to air filter restriction or turbo issue
- Step 1: Exhaust smoke diagnosis. Step 2. Black smoke indicates unburned fuel from insufficient air (clogged air filter, faulty turbo, leaking injector). Answer: Fuel-rich mixture combustion due to air filter restriction or turbo issue. Why not the others: Low oil produces blue smoke; coolant in cylinders produces white steam; efficient operation produces clean exhaust.
Practise more Driving Safety, Emergency Response and Vehicle Operation.
Free questions with an explanation for every one, and full timed Vozački ispit (Driving Theory Test) - Croatia mock tests.
More Driving Safety, Emergency Response and Vehicle Operation questions
- What two main components constitute the total stopping distance of a motor vehicle?
- How does doubling the travel speed affect the braking distance of a passenger vehicle?
- What is the primary function of an Anti-lock Braking System (ABS) during emergency braking?
- What sensation is normal for the driver when ABS activates during heavy emergency braking?
- What phenomenon occurs when tires lose contact with the road due to a water layer?
- What is the correct driver reaction when experiencing sudden aquaplaning?