5 gas diagnostics what goes in must be consumed, if not it comes out! steve zack
TRANSCRIPT
The Theory of 5 Gas
• Air Contains 77% to 78% Nitrogen, N2
• N2, 2 Elements of N
• N2 Absorbs Heat– In the Atmosphere– In the Combustion Chamber
• N2 Separates Under Pressure and Temperature
The Theory of 5 Gas
• Remaining Air Contains 21% Oxygen, O2• O2, 2 Elements of O• O2 is an Oxidizer• Remaining Portions of Air
– Argon, Ar– Helium, He– Hydrocarbons, HC – Etc.
The Theory of 5 Gas
• Intake Valve Opens Exposing Low Pressure
• Injector Sprays Atomized HC
• HC, Gasoline– 1 Element of H - Hydrogen – 1 Element of C - Carbon
• 14.7 Psi Pushes Air and Fuel in
H C
Gasoline - HC
The Hexane Value Gas Analyzers Measure
Atomized
Liquid
GASOLINE FORMULA: 27% AROMATIC (BENZENE C6H6), 12% OLEFINS (CnH2n), 1% BENZENE (C6H6), 305PPM SULFUR (S), 11% MTBE (METHYL TERTIARYBUTYL ETHER), 2% OXYGEN (O)
The Theory of 5 Gas
• Piston Rises in Compression Stroke, Pressure Builds
• The Compounds Will Rub Together
• This Causes Friction of the Elements
• Friction Causes Heat
The Theory of 5 Gas
• Heat Absorbed by the Elements
• O2 Absorbs Heat Separates to O and O
• HC Absorbs Heat Separates to H and C
• O2 and HC Now Vapor
The Theory of 5 Gas
• Piston Continues to Rise
• Friction Causes 2300 F
• Pressure has Increased
• N2 Will Absorb Heat at 2300 F
• N2 Will Separate to N and N, Now Vapor
The Theory of 5 Gas• The Spark Plug Ignites, Pressure Increase
– Voltage is Pressure
• The O Elements Will Oxidize with N, C, and H– 2O Elements to 1C Element = CO2
– 1O Element to 2H Elements = H2O
– XO Elements to 1N Element = NOx
• Oxidation, O Elements Attaching to Other Elements
The Theory of 5 Gas
• Oxidation Creates as the Elements Collide
• All the Combined Appear as
• Oxidation Creates Energy Through Heat
• The Heat Energy Forces the Piston Down
Sparks
Sparks
Fire
The Theory of 5 Gas
• As Combustion Occurs a Good Running Engine Produces
– H2O - 2 H - Hydrogen Elements and 1 O - Oxygen Element
– CO2 - 1 C - Carbon Element and 2 O - Oxygen Elements
The Theory of 5 Gas
• As Result of Driving Conditions Most Engines Will Produce – H2O
– HC - 1 H - Hydrogen Element and 1 C - Carbon Element
– CO - 1 C - Carbon Element and 1 O - Oxygen Element
– O2 - 2 O - Oxygen Elements
– CO2
– NOx - 1 N - Nitrogen Element and Unknown O - Oxygen Elements
The Theory of 5 Gas
• The Catalytic Converter Will Oxidize and Reduce– HC to H2O and CO2– CO to H20 and CO2– NOx to CO2 and H2O and N2
O2 SENSOR READS RICH , PCM COMMANDS LEAN, REPLENISHING CATALYTIC CONVERTOR WITH O2
800mv SWITCH <100ms
Diagnosing 5 Gas - HC
• Causes– Rich
– Contaminated Crankcase
– Lean
– Secondary Ignition• Spark Plugs
• Plug Wires
• Cap & Rotor
– Primary Ignition• Coil
• Low Primary Current
– Base Timing
• Causes– Preignition
– Charging System
– EGR
– Cooling System
– Engine Problems• Valves
• Rings
– Cam Timing
– Carbon• Intake Valve Throat
Diagnosing 5 Gas - CO• Causes
– Rich• MAP or MAF• TPS• IAC Closed• Injector Spray• Air Cleaner
– Evaporative Purge System– Contaminated Oil– Charging System– Engine Problems– Cam Timing– Base Timing
• Retarded
Diagnosing 5 Gas - O2• Causes
– Lean• IAC Open• Vacuum Leak• Injector Spray• Fuel Volume
– Secondary Ignition– Primary Ignition– Base Timing– Preignition– Charging System– Cooling System– Engine Problems– Exhaust Valve– Carbon – Exhaust Leak
• Dilution
N O NO
O
+ = NOx
NO + NO2 = NOx
A Product of Combustion
NOx
Oxides of Nitrogen
Brown Color, Toxicant
Nitrogen Dioxide
Colorless, Odorless, Toxicant
Nitrogen Oxide
Diagnosing 5 Gas - NOx• Causes
– Lean
– Base Timing• Advanced
– Preignition
– EGR• EGR Flow
– Cooling System• Pump Vanes• Thermostat• Fan & Fan Belts• Coolant Level & Quality• Jacket Corrosion
– Cam Timing
– Exhaust Valve
– Carbon• Cylinder & Piston
Summary• NOx HC CO O2 CO2
• Rich L H H L L• Contaminated Oil L H H L L• Lean H H L H L• Secondary Ignition L H L H L • Primary Ignition L H L H L• Base Timing H H L H L• Preignition H H L H L• Charging System L H H H L• EGR H H L L L• Cooling System H H L H L• Engine Problems L H H H L• Cam Timing H H H L L• Exhaust Valve H H L H L• Carbon H H L H L• Exhaust Leak L L L H L• Test at 1000 RPM, Engine at Operating Temperature, H - High, L - Low
Fuel, OBD
Ignition
OBD
Mechanical
Summary
• NOx < 150 PPM to 300 PPM Max
• HC < 100 PPM Max
• CO < 0.5 % Max
• O2 < 0.5 % Max
• CO2 > 12 % to 15 % Min• Test at 1000 RPM, Engine at Operating Temperature
• Testing After the Catalytic Converter