failed emissions for HC?

[shogun]

Read this from Bosch:

5 Gas Analysis

Bosch Technologies Group 2003
Three Reasons for Gas Analysis

* Identify engine performance and mechanical problems
* Test the running efficiency of the engine
* Test for exhaust emissions against state and federal standards

Combustion Chemistry and Gas Analysis.

* The combustion process releases the energy stored in the fuel
* Fuels consist basically of carbon(C) and hydrogen(H) referred to as hydrocarbons (HC).
* Under ideal conditions all of the HCs would be converted to H2O, CO2 and heat.



Combustion Chemistry and Gas Analysis.

* Unfortunately this complete combustion is rarely if ever achieved
* Short burn times, continuously changing mixture ratios and air temperatures, and combustion chamber quenching produce conditions which give rise to the formation of pollutants

Pollutants

* Incomplete combustion produces carbon monoxide (CO)
* Unburned fuel produces hydrocarbons (HC)
* High combustion temperatures produce oxides of nitrogen (NOX)

Other Exhaust Gases

* Carbon dioxide (CO2) is a product of complete combustion. Therefore the higher the level of CO2 the more efficient the engine is running.
* Oxygen (O2) level in the exhaust indicates the fuel-air mixture.

High O2=lean

Low O2=Rich

Gas Analysis as a Diagnostic Tool



Gas analysis

* Is a quick and accurate way to determine the running conditions of an engine
* By observing the 5 gas readings and understanding their relationship to each other you can diagnose the 3 major engine areas:

Fuel delivery

Ignition

Engine Mechanics


High HC Only


Hydrocarbons are unburned fuel. This can be caused by:

Ignition Timing (base and advance)

Vacuum Leaks (hoses, brake booster, manifold, evap. etc.)

Ignition (misfires, coil breakdown, etc.)

Mechanical (low compression, bad cam, etc.)

Catalytic Converter Failures


High CO Only


* Carbon Monoxide is a result of incorrect fuel/air mixtures. Causes include:
* For Carburetors (float level, power circuit, choke circuit)
* For Injection (injectors, pressure regulator, temp sensor, MAP/MAF sensor)
* For Both Systems (air filter, PCV, Evap, O2 sensor, air injection



High Nox Only


* NOX is caused by high combustion chamber temperatures. Check:
* EGR (valve, controls, solenoids, passages, vacuum hoses)
* Ignition Timing ( base and advance)
* Engine Temperature (cooling system, fan restricted exhaust, Thermostat)
* Vacuum Leaks (hoses, booster, evap, etc)
* Mechanical (carbon deposits, converter, etc)

High CO and HC


* Normally, when HC and CO are high it is the result of a CO failure driving the HC high.
* Correct for high CO first (Excessive fuel, restricted air, Evap., etc.)
* If HC is still high, test as high HC (ignition, timing, mechanical, etc.)



High CO and Nox

* These problems are normally incompatible. If they occur on the same test they will most likely occur at different points on the drive cycle
* Correct CO failure first
* Retest and locate NOX failure in drive cycle and correct as NOX failure only



HC and NoX

* High HC and NOX normally occur as the result of a lean misfire. Check for:
* Lean run (vacuum leaks, mixture problems, fuel delivery, etc.)
* Mechanical (oil burning can cause high combustion chamber temperatures)



CO, HC and NOX

* This is a complete breakdown of the emission systems or multiple failures. Check:
* Catalytic Converter (missing, damaged)
* PCM (closed loop, wiring, etc.)
* Drive cycle ( if failures occur at different points diagnose each failure separately)

[stephenlc]

Well I am a state inspector, could you post your other readings, and I could tell you what most likely wrong with the car. First I would check for vacuum leaks you can do this is with a spray bottle with water. Start the car and spray most of the engine, look at the vacuum hoses and check for any of them sucking in water. It will make a hissing sound, and if you find a hissing vacuum hose replace it. If you can't find any leaking hoses, check the condition of your spark plugs. If one is fouled are they have lots of black soot on them, just go ahead and replace all of them, you can buy cooper ones for about 2 dollars each. Then check your coil packs but I doubt those are bad. You are going to have to post the numbers and limits so I can get a better idea of whats wrong.

[shogun]

Someone tried this one or has better recommendation for a DIYer?

Automotive Combustion Leak Detector by Lisle


SKU: LIS-75500

Quickly Pinpoints Automobile Combustion Leaks.
Checks for combustion leaks caused by bad head gaskets, cracked blocks, and cracked or warped heads. Fluid changes from blue to yellow when exposed to combustion gases from the radiator. Connect the hose to any vehicle vacuum line. Or, on tools made after June 2002, use the red adapter with a hand vacuum pump. Place tapered end of tool into radiator opening. With the engine running, the vehicle vacuum or the vacuum pump draws vapors through the indicating fluid for testing. Diesel adapter included.

http://www.tooldesk.com/products/pro...l.aspx+id+1800

[Bellicose Right Winger]

I've never used it, but the cost is very reasonable. My head gasket failures left no doubt where problem was.
The mfr has some photos of device in use.
http://www.lislecorp.com/tool_detail.cfm?detail=1332
http://www.lislecorp.com/tool_detail.cfm?detail=1335

Paul Shovestul

Someone tried this one or has better recommendation for a DIYer?

Automotive Combustion Leak Detector by Lisle


SKU: LIS-75500

Quickly Pinpoints Automobile Combustion Leaks.
Checks for combustion leaks caused by bad head gaskets, cracked blocks, and cracked or warped heads. Fluid changes from blue to yellow when exposed to combustion gases from the radiator. Connect the hose to any vehicle vacuum line. Or, on tools made after June 2002, use the red adapter with a hand vacuum pump. Place tapered end of tool into radiator opening. With the engine running, the vehicle vacuum or the vacuum pump draws vapors through the indicating fluid for testing. Diesel adapter included.

http://www.tooldesk.com/products/pro...l.aspx+id+1800

[shogun]

@stephenlc

My car(s) have no problem at all!

I just would like to have comments of people who know this/have tried this or other equipment:
Automotive Combustion Leak Detector by Lisle

or if there is something better for a DIYer in a similar price range or better/easier to handle.

Thanks anyway for your comments.

[shogun]

Thanks Paul,

probably I will buy one, looks easy to use and the price is reasonable.