Fuel Injection Flashcards
(35 cards)
Approx fuel pressure for multi port fuel injection systems is:
a. 15-25 psi b. 25-35 psi c. 35-45 psi d. 45-55 psi
c. 35-45 psi
Throttle body fuel injection systems’ approx. fuel pressure is:
a. 7-15 psi b. 15-25 psi c. 25-35 psi d. 35-45 psi
a. 7-15 psi
Pulse width is determined by what on throttle body injection systems in closed loop?
a. Engine coolant temperature sensor b. Oxygen sensor c. MAP sensor d. Throttle position sensor
b. Oxygen sensor
When an injector circuit is fully grounded, the injector is:
a. Closed b. Open c. Half open d. Half closed
b. Open
What would happen if a coolant temperature sensor has an open?
a. Rich fuel mixture b. Lean fuel mixture c. Stoichiometric fuel mixture d. Oxygen sensor controlled
a. Rich fuel mixture
What is the first step to repair a fuel injection problem?
a. Use a scan tool b. Visual inspection c. Verify complaint d. Drive the vehicle into the work shop
c. Verify complaint
What is the fuel pressure for direct fuel injection systems?
a. 25-30 psi b. 30-35 psi c. 40-45 psi d. 50 or more psi
d. 50 or more psi
What is a hot wire used to measure?
a. Liquids b. Air flow c. Friction d. Pressure
b. Air flow
A TPS are most commonly (blank) type sensors:
a. Thermistor b. Potentiometer c. Piezoelectric device d. Resister
b. Potentiometer
The PCM will adjust the idle air control valve based on the:
a. Engine RPM b. Engine load c. Vehicle speed d. All of the above
d. All of the above
As the manifold pressure on an engine rises, the output voltage on a variable resistance MAP sensor will:
a. Increase b. Decrease c. Stay the same d. No difference
a. Increase
A throttle body injection (TBI) system may also be referred to as a/an:
a. Electronic fuel injection system b. Central fuel injection system c. Digital fuel injection system d. All of the above
d. All of the above
An oxygen sensor cycles between 100mv to 800mv. What best describes the operation of the oxygen sensor?
a. Reading rich b. Reading lean c. Reading normal d. Reading stoichiometric
c. Reading normal
An OBD2 equipped vehicle has an exhaust leak at the manifold. What will the oxygen sensor read?
a. Read rich b. Read lean c. Read normal d. Read stoichiometric
b. Read lean
What could be the fault if both the primary and secondary oxygen sensors are within harmony to each other?
a. Bad secondary oxygen sensor b. Both oxygen sensors are normal c. Bad catalytic converter d. Exhaust leak
c. Bad catalytic converter
What are the procedures to check for EGR valve operation?
a. Energize the valve and observe idle quality b. Pressurize the valve and observe idle quality c. Energize the valve and look at the scan tool d. Pressurize the valve and look at the scan tool
a. Energize the valve and observe idle quality
A plugged EGR tube will cause:
a. High CO b. High HC c. High NOx d. High CO2
c. High NOx
An OBD2 vehicle has a check engine light on for an EGR valve failure. After replacing the EGR valve, how do you confirm that EGR operation is ok?
a. Run the vehicle until closed loop b. Run the vehicle in open loop c. Road test vehicle to set drive cycle d. Scan the EGR valve with a scan tool
d. Scan the EGR valve with a scan tool
How is a mass air flow sensor tested with a DVOM?
a. DVOM in series and set to voltage b. DVOM in series and set to amperage c. DVOM in parallel and set to frequency d. DVOM in parallel and set to amperage
c. DVOM in parallel and set to frequency
After replacing a MAF sensor, the vehicle experiences starting and stalling issues. Which of the following could be the cause?
a. Air leaks at the MAF sensor b. Air filter is dirty c. Worn motor mount d. Defective MAF sensor
a. Air leaks at the MAF sensor
A vehicle is towed in for a no start. The tech tests the fuel pressure and finds the fuel pressure rises and drops to zero after key ON. Which of the following can cause this problem?
a. Fuel pump check valve stuck closed b. Fuel pump check valve stuck open c. Fuel pump relay d. ECM
c. Fuel pump relay
Without the use of a scan tool, how can a MIL indicator light be turned off?
a. 5 on/off cycles of the ignition b. 40 drive cycles c. 5 drive cycles d. Key on and moving the gear shifter
b. 40 drive cycles
If the MIL light comes ON during a test drive, what should you do?
a. Stop the vehicle and tow back to the shop b. Drive the vehicle back to the shop and continue with repairs c. Not worry about the light d. Check oil level
b. Drive vehicle back to the shop and continue with repairs
What is the difference between a MIL light ON and Flashing?
a. Nothing b. Flashing MIL is damaging the catalyst c. Transmission problem d. Brake problem
b. Flashing MIL is damaging the catalyst
