× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
g
3
3
r
3
2
J
2
p
2
m
2
h
2
s
2
r
2
d
2
l
2
New Topic  
aantonopoulos aantonopoulos
wrote...
Posts: 38
Rep: 0 0
5 years ago
1.   Which one of the following is a prime source of problems in secondary air systems?
    
A. Engine coolant
B. Engine oil
C. Water
D. Dirt

2.   The positive crankcase ventilation (PCV) system helps reduce _______ exhaust gas emissions.
    
A. NOx (oxides of nitrogen)
B. oxygen
C. HC (hydrocarbon)
D. CO2 (carbon dioxide)

3.   Which of these engine concerns may be caused by a stuck-open exhaust gas recirculation (EGR) valve?
    
A. Excessive NOx exhaust emissions
B. Engine missing at highway speed
C. Ping (spark knock or detonation)
D. Rough idle/stalling

4.   The _______ valve protects the air pump from reverse-exhaust pressure.
    
A. check
B. diverter
C. gulp
D. positive crankcase ventilation (PCV)

5.   Which of these items will least likely increase pressure in the evaporative emission control system?
    
A. Volatility of the fuel
B. Returned fuel from the fuel-injection system
C. Fuel temperature
D. Inlet fuel to the fuel pump

7.   A technician suspects that the exhaust gas recirculation (EGR) valve is closed. Which of the following would indicate a closed EGR valve?
    
A. Rough idle
B. Stalling
C. Spark knock
D. Engine surge
 

8.   Which of these evaporative control valve(s) is/are normally open?
    
A. Canister vent valve
B. Canister purge valve
C. Neither the canister purge nor canister vent valve
D. Both the canister purge and canister vent valve

Read 942 times
6 Replies

Related Topics

Replies
wrote...
5 years ago
2.   The positive crankcase ventilation (PCV) system helps reduce _______ exhaust gas emissions.
    
A. NOx (oxides of nitrogen)
B. oxygen
C. HC (hydrocarbon)
D. CO2 (carbon dioxide)

The Positive Crankcase Ventilation (PCV) system helps reduce air pollution by aiding in the scavenging and burning of harmful engine crankcase vapors and gases before they can enter the atmosphere. The PCV system consists essentially of an intake filter, PCV valve and interconnecting hoses.

I'm thinking C.
wrote...
5 years ago
1.   Which one of the following is a prime source of problems in secondary air systems?
    
A. Engine coolant
B. Engine oil
C. Water
D. Dirt

C - Water is one of the prime sources of problems in these systems. There are two typical causes of water contamination. The first cause is failure of the reed valve to seal due to breakage or loss of temper, allowing water from the exhaust to enter the A.I.V. case. Second, the reed valves can also stick closed, preventing air from getting to the catalyst.
wrote...
5 years ago
3.   Which of these engine concerns may be caused by a stuck-open exhaust gas recirculation (EGR) valve?
    
A. Excessive NOx exhaust emissions
B. Engine missing at highway speed
C. Ping (spark knock or detonation)
D. Rough idle/stalling

Rough idling and problems with acceleration are the two most common indicators that the EGR valve is stuck open. The truck might also stall excessively. When the EGR valve is stuck open, all of the exhaust gas cycle back into the chamber, meaning there’s not enough oxygen for a combustion to take place.

If in the closed position: This means that the EGR valve is stuck shut and refuses to open. There will be increased nitrous oxide gas which will create engine knocking.
wrote...
5 years ago
4.   The _______ valve protects the air pump from reverse-exhaust pressure.
    
A. check
B. diverter
C. gulp
D. positive crankcase ventilation (PCV)

https://biology-forums.com/index.php?topic=399331.0
wrote...
5 years ago
7.   A technician suspects that the exhaust gas recirculation (EGR) valve is closed. Which of the following would indicate a closed EGR valve?
    
A. Rough idle
B. Stalling
C. Spark knock
D. Engine surge

Spark knock

Spark knock is a symptom of an EGR valve that is always closed. The other choices are wrong because they are symptoms of an EGR valve that is always open.
wrote...
5 years ago
8.   Which of these evaporative control valve(s) is/are normally open?
    
A. Canister vent valve
B. Canister purge valve
C. Neither the canister purge nor canister vent valve
D. Both the canister purge and canister vent valve

I think it's A
New Topic      
Explore
Post your homework questions and get free online help from our incredible volunteers
  1022 People Browsing
 166 Signed Up Today
Related Images
  
 793
  
 391
  
 320