Brake Bleeding Lab - Community College of Philadelphia



AT 261 - Chapter 14 Emissions Systems Diagnosis

Name: _________________________________________

Date: __________________________________________

(PCV System and Inspection

Tools you will need:

Tool Board

2001 Ford Windstar (Black)

( Inspect the air filter and check for oil contamination

(A faulty or missing PCV will cause oil to be present in the air cleaner housing on most engines. Excessive oil consumption is another sign of a faulty PCV valve.

( Locate the PCV valve on this vehicle

( Inspect for dirt deposits that could clog the passages in the intake manifold where the PCV valve hose runs into the intake.

( Remove the hose and make sure it is clear and fairly solid.

( A clogged or "soft" hose will tend to collapse when the PCV system is in operation. This restriction will cause crankcase vapors to build up in the engine. This pressure will cause the engine to "blow" seals and leak oil.

( Start the engine.

( Disconnect the PCV valve from the valve cover, and then remove the PCV from the intake hose

(The idle will rise - as you just caused a vacuum leak in the intake manifold!

( Confirm that the line is hissing, indicating airflow.

( Place a finger over the end of the line to confirm vacuum at the valve.

( If you did not feel vacuum either the hose or intake passage is clogged.

( Shut the engine off, and shake the valve. It should rattle.

( If the PCV system is missing or inoperative, this will cause higher than normal HC and CO readings in the exhaust. If the valve does not rattle, it indicates a valve that is stuck closed.

( Reconnect the valve to the end of the hose. Leave the valve OUT of the valve cover

( Restart the engine; note the position of the valve. Is it open or closed? ______________________

( Slightly raise the idle and watch the valve, what happens to the position of the valve?

______________________

Is this PCV system operational?

_________________________.

Q(

Thus we can conclude that at idle the valve is normally ______________________, and at higher speeds and low

vacuum the valve is _____________________. This allows ___________________________ to vent from the

crankcase into the ________________________ and be burned.

Problems with the PCV Valve may be;

A. Collapsed PCV line

B. Stuck open or closed valve

C. Incorrect valve

D. All of the above

A problem with the PCV valve will cause;

A. NOx, HC, CO, and O2

B. CO, HC, blown seals, excessive blowby in the crankcase, oil in air filter chamber, and excessive oil consumption

C. CO2, HC, blown seals, excessive blowby in the crankcase, oil in oil filter

D. HC, H2O, overheated converter and dirty air filter

If a PCV is defective it may; (circle all the apply)

A. Cause oil pan gaskets, rear main seals, and front main seals to fail

B. Cause higher than normal NOx readings

C. Cause higher than normal HC readings

D. Cause engine sludge

(Instructor’s Signature _________________________________________________________________

(EGR System and Inspection (On Car)

Tools you will need:

2001 Ford Windstar (Red)

Hand vacuum pump

( Locate the EGR valve

( Inspect the following components, EGR valve body, Exhaust Tubing, and vacuum line.

( Are there any defects? ________________________

( The BEST test for an EGR valve is to monitor it with a scan tool. However, since the vehicle must meet certain operating parameters - this is not practical in a class room situation.

What are the parameters for EGR to open?

Engine at ______________ RPM

Coolant at ______________ deg F

Engine load at __________________ %

( Disconnect the green vacuum line from the EGR valve.

( Follow the vacuum line from the EGR to another component. What is this component? ___________________

Look at the schematic for this engine; what is this component called, and what are its wire colors/codes off the PCM?

_______________________________________________________________________________

( Connect the vacuum pump to the EGR valve.

( Apply 15" of HG to the valve.

Does it hold vacuum for at least 20 seconds? _________________________

( Release the vacuum.

( Start the vehicle

( Once the vehicles reaches normal idle - SLOWLY apply vacuum to the EGR valve (no more than 5-7" HG)

What happens? _______________________________________

( Apply full vacuum to the valve (15-20" HG)

What happens? _______________________________________

(The EGR valve should cause the vehicle to stall. This happens because exhaust gas is being fed back into the intake at idle - not when the EGR valve would normally be open. A stuck open EGR valve or a valve that opens at the wrong time can cause a vehicle to stall.

A valve that never opens will cause the combustion chamber to get too hot, and cause excessive NOx. This can be caused by defected control systems (vacuum lines, solenoids.. etc..), lack of signal from the PCM, carbon buildup in the EGR valve, or bad EGR valve diaphragm.

A ripped diaphragm in the EGR valve would cause it to not move when needed.

Based on this method of testing, does this EGR valve operational? ______________________________

(Instructor’s Signature _________________________________________________________________

(EGR System and Inspection (Off Car)

Tools you will need:

EGR valves

Hand vacuum pump

Using the hand pump, test the EGR valves on the table. Inspect them for proper operation, or carbon buildup.

Valve 1 Ok – Not OK Carbon Other: _______________________________________

Valve 2 Ok – Not OK Carbon Other: _______________________________________

Valve 3 Ok – Not OK Carbon Other: _______________________________________

Valve 4 Ok – Not OK Carbon Other: _______________________________________

Valve 5 Ok – Not OK Carbon Other: _______________________________________

Valve 6 Ok – Not OK Carbon Other: _______________________________________

Q(

A stuck closed EGR valve will cause high ____________ emissions.

A. NOx

B. CO

C. CO2

D. HC

The EGR functions,

A. At cold startup, 2000 RPM, Idle and WOT, 50% Engine Load

B. At hot/warm engine, 1500 RPM, part cruise, and 30% Engine Load

C. At overheating engine, 2000 RPM, WOT, and 40% Engine Load

D. At warm engine, 5000 RPM, Idle, and 50% Engine Load

Problems with the EGR Valve may be;

A. Carbon buildup in the ports

B. Missing or damaged vacuum diaphragm

C. Damaged solenoid

D. All of the above

(Instructor’s Signature _________________________________________________________________

(Evaporative Emissions Testing (Canister Purge)

Tools you will need:

2001 Honda Accord

Shop Manual

Locate the basic parts of your evaporative emissions fuel system, write down their locations. - Use pages 11-22 and 11-142

Purge Control Valve: ______________________________________

Fuel Cap: _____________________________________

Fuel Tank: _______________________________________

Charcoal (EVAP) Canister: ___________________________________

Two Way Valve (liquid/vapor separator) _________________________________

How many vacuum lines run to the charcoal canister? ______________

Where do these lines run? _____________________________________________________________________

What are the wire colors/codes off the PCM of the Purge Control Solenoid? _________________________________

Q(

Canister Purge;

A. Allows fuel vapors from the fuel tank to be stored and burned in the intake manifold.

B. Allows oil vapors from the fuel tank to be stored and burned in the intake manifold.

C. Allows oil vapors from the fuel tank to be stored and burned in the exhaust manifold.

D. Allows fuel vapors from the fuel tank to be stored and burned in the exhaust manifold.

A damaged canister (Stuck open) purge circuit will cause high ____________ emissions.

A. NOx

B. CO

C. CO2

D. HC

(Instructor’s Signature _________________________________________________________________

(Solenoid Inspection (Off Car)

Tools you will need:

Vacuum control valves

DVOM

12V Battery

Hand vacuum pump

Using a DVOM, measure the solenoid resistance of each valve.

Solenoid 1 _______________________________________________________

Solenoid 2 _______________________________________________________

Solenoid 3 _______________________________________________________

Using the hand pump, test the solenoid valves on the table. Try to apply 20" of vacuum to each valve.

Solenoid 1 _______________________________________________________

Solenoid 2 _______________________________________________________

Solenoid 3 _______________________________________________________

Using the battery back and a fused jumper wire, jump 12 volts to each solenoid. You should hear a "click"

Solenoid 1 _______________________________________________________

Solenoid 2 _______________________________________________________

Solenoid 3 _______________________________________________________

Using the hand pump, test the solenoid valves on the table. Try to apply 20" of vacuum to each valve. While the valve is holding vacuum, jump 12 volts to the solenoid. What happens?

Solenoid 1 _______________________________________________________

Solenoid 2 _______________________________________________________

Solenoid 3 _______________________________________________________

Based on these conclusions, what can you determine about the operation of these valves?

Solenoid 1 OK – Not OK

Solenoid 2 OK – Not OK

Solenoid 3 OK – Not OK

NATEF TASKS - VIII. ENGINE PERFORMANCE

VIII. ENGINE PERFORMANCE

E. Emissions Control Systems Diagnosis and Repair

1. Positive Crankcase Ventilation

1. Diagnose oil leaks, emissions, and driveability problems resulting from malfunctions in the positive crankcase ventilation (PCV) system; determine necessary action. P-2

2. Inspect, test and service positive crankcase ventilation (PCV) filter/breather cap, valve, tubes, orifices, and hoses; perform necessary action. P-2

2. Exhaust Gas Recirculation

1. Diagnose emissions and driveability problems caused by malfunctions in the exhaust gas recirculation (EGR) system; determine necessary action. P-1

2. Inspect, test, service and replace components of the EGR system, including EGR tubing, exhaust passages, vacuum/pressure controls, filters and hoses; perform necessary action. P-1

3. Inspect and test electrical/electronic sensors, controls, and wiring of exhaust gas recirculation (EGR) systems; perform necessary action. P-2

3. Exhaust Gas Treatment

1. Diagnose emissions and driveability problems resulting from malfunctions in the secondary air injection and catalytic converter systems; determine necessary action. P-2

4. Evaporative Emissions Controls

1. Diagnose emissions and driveability problems resulting from malfunctions in the evaporative emissions control system; determine necessary action. P-1

2. Inspect and test components and hoses of evaporative emissions control system; perform necessary action. P-2

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