ADT ADT Fuel System & Injection Technology

Question 1

Audi's TFSI engine technology combines which two fuel delivery methods to improve efficiency and performance?

Accepted Answer

Turbocharging and Gasoline Fuel Stratified Injection (direct injection)

Answer

Twin turbocharging and port injection only

Answer

Supercharging and carburetion

Answer

Turbocharging and throttle body injection

Question 2

On Audi FSI/TFSI engines, the high-pressure fuel pump is driven by:

Accepted Answer

A lobe on the camshaft

Answer

The crankshaft belt directly

Answer

An electric motor

Answer

The power steering pump

Question 3

What is the typical high-pressure fuel rail operating pressure range for Audi TFSI direct injection engines?

Accepted Answer

50–200 bar

Answer

3–5 bar

Answer

10–15 bar

Answer

0.5–1 bar

Question 4

A customer's Audi A4 2.0 TFSI exhibits rough idle and misfires at cold start. A known common cause on this engine is:

Accepted Answer

Carbon buildup on intake valves due to direct injection without port wash

Answer

Failed MAF sensor only

Answer

Low octane fuel

Answer

Vacuum leak at the brake booster

Question 5

When diagnosing a low fuel pressure code on an Audi TFSI, a technician should verify which component FIRST?

Accepted Answer

The low-pressure fuel pump (in-tank pump) output pressure

Answer

The high-pressure injector resistance

Answer

The throttle body position

Answer

The crankshaft position sensor signal

Question 6

On Audi EA888 Gen 3 engines, a 'dual injection' system combines direct injection with port fuel injection (PFI). What is the PRIMARY benefit of adding port injectors?

Accepted Answer

Port injectors wash intake valves with fuel, preventing carbon buildup

Answer

They replace the direct injectors at high load

Answer

They reduce turbocharger boost pressure

Answer

They allow the engine to run on diesel fuel