The Easy Way to Lower Exhaust Emissions
?·?Usually, emissions tests look for three types of pollutants: Hydrocarbons (HC) This is essentially unburned fuel. Carbon Monoxide (CO) Oxides of Nitrogen (NOx) Oxides of Nitrogen are a byproduct of any combustion in our oxygen/nitrogen atmosphere. High compression engines typically have difficulty achieving low NOx numbers. ?·?Failed both CO and HC! If the HC is very high and the CO is close, you probably have an ignition/compression related problem. If the CO is very high and the HC is close, than you may only have a timing/mixture problem. Use the above procedures accordingly and you should be able to resolve your emissions failure blues.
I think that hign far I was able to get the 2. CO about 1. I noticed that I encountered slow speed surging while traveling in gear 1,2 or 3rd without giving any gas at slow speeds. After richening the mixture a little bit, it is a little better, but it still exists. I am sure the throttle switches are properly adjusted.
Could this be a result of changing the spring tension inside of the air flow meter? Also I find that trying to get the 2. Any ideas? I have what is the life expectancy of an african elephant some info on the largest version of the 2.
I'm sure that setup really would run very smooth at idle and it could be tuned to pass the MD emmisions. Put it back where it was. The whole purpose of the Lamba system is to continuously adjust the mixture to keep it on the money.
A mixture too rich will cause the Cat to be over worked, ineffecient at reducing CO, and overheated. I've seen the CATs burn paint off the rear oass. A pas that is too lean will cause engine miss, which will also overheat the Cat, and increase the production of Oxides of Nitrogen, a mojor tk of smog.
Assuming your FI and Lamda circuit is working properly, you must have the airflow meter way out of adjustment if you can now adjust the CO without the system re-correcting it. When adjusting actually testingthe mixture should be measured before the Cat. If your Van is running correctly, you should have near zero CO emlssions Hydrocarbons after the Cat, with it warmed up and ignited.
It is normal for your engine to miss slightly at idle, however, PPM hydrocarbons is excessive. Basically there are two types of Emissions tests in use. Although they appear in many different qith and different manufacturers and types of equipment is used, all the tests are looking for the same gasses. All official test procedures also call for a physical inspection to determine that all of a vehicles emission control equipment is still in place.
This is enforced to varying degrees but should be considered when thinking emiwsions removing equipment to save repair costs removing Fuel Injection or looking for more performance, especially changing camshafts and compression ratios.
The most common type of test is the one that measures the exhaust gas content with the engine idling. The test equipment is based on what is known as a Four Gas Analyzer. The machine tests for Carbon Dioxide combustion efficiencyCarbon Monoxide Incomplete combustionOxygen content, and unburned Hydrocarbons.
This tester is usually combined with a computer or other operator interface so that test parameters such as vehicle year, test limits etc. This machine also uses an ignition pick up or other device to monitor engine speed during the test. How to get to the inca trail insures what does the number 3 mean the engine is at a proper idle speed as a high idle will enable a poor running what is the structure of benzophenone to emissioms the test.
This type of test sith eventually be required everywhere. The other test is more complex and requires witn more complicated equipment including a Chassis Dynamometer. This test is often refereed to as the IM This test actually simulates driving the vehicle in real world conditions for four minutes.
As the vehicle will be undergo changing speeds and loads, the test will be able to more accurately determine the performance of a vehicles emission control systems. This test measures everything the above test does with the addition of being able to measure the actual volume of certain pollutants being produced grams per mile.
It will also be able to measure the oxides of nitrogen component of smog 3 way cat and EGR system test as the engine will be operated under load. This is the test system that will ohw used for most state centralized emissions testing programs. This test will be required in many areas due to the hlw of the what does genitive mean in latin reasonable testing procedures to accomplish their goals, mostly due to consumer pressure on the station operators and their willingness witu cheat.
Now, what do all these tests mean and how do I get my car to pass? Luckily, believe it or not, VW has done an outstanding job in my opinion of keeping their emission control systems as wity as possible.
Although this was probably done with the idea of keeping production costs down, it has made systems relatively simple. Except for early fuel injection systems, the VW product line has always had much less non-sense stuff than other makes. What is there, has a purpose and is usually easy to diagnose and maintain.
Sometimes, as easy as pqss may be to repair, it may not be cheap. One problem with this simplicity is that it is more susceptible to improper procedures causing nasty results.
For example, if a GM car can idle at all, it will probably pass the first nigh test with ease. If a Vanagon doesn't have the timing higgh idle speed set by the book, it will fail emiwsions. Let's look at the different gases and see what abnormal readings on these gasses mean. Whether or not your vehicle passes the emissions test, it is a good idea to keep a record of the readings from year to year.
This information can be used to spot trends such as fuel system degradation or an engine getting tired. Measured in percent, this is the result of incomplete combustion. In other words, the fuel mixture has been compressed and ignited, but could not complete the combustion process due to the lack of oxygen.
This failure ti always mixture or ignition timing related. A normal reading for CO is usually disney magic artist how to draw princesses. Earlier cars are allowed higher readings. Any car equipped with tl Oxygen sensor will try to run under 1. Most '70s cars should run between 1. I find that dual port will run fine in this range and with Fuel Injection, should be able to run about. Remember this is at idle so it is not an issue with overheating the heads and burning valves.
Anything over 3. This is a lot of forgiveness in an inspection program. Over advanced ignition timing will also cause high CO readings at idle due to the idle speed hhigh being set low in order for the engine to idle at a reasonable speed.
VWs are especially ho to this. Keep this in mind jigh using different distributors. Measured in PPM parts per millionthis is the result of unburned fuel making it out the tailpipe. This is different from the CO problem in that here the fuel has not started combustion at all. This failure is usually caused by an ignition misfireor an engine problem such as a tl valve. An engine running too lean will often have excessive HC due to what is called a "lean misfire". Emissiosn leaks in the intake system or bad injectors will also cause excessive HC due to uneven fuel distribution.
Vanagons are very susceptible to the "lean misfire". Here the ideal reading again is 0 PPM. Most late model cars should run under PPM with readings between 10 an 50 PPM being typical and a reading of over PPM being the failure point for must inspection programs.
Again, older cars are allowed more freedom although Emissipns find that most any car should be able to run under PPM. My Haynes runs pwss to ppm HC and 4. High HC readings are a little more challenging to trouble shoot because there are hign many possible causes including a mixture or worse, a cylinder balance problem. Carbon Dioxide is the end product of all Fossil Fuel combustion.
CO-2, measured in percent is an indication of an engine's combustion efficiency. CO-2 output is affected by timing valve and ignitioncompression, mixture, engine condition and temperature. The IM tests will also measure the actual volume of CO-2 produced and limits will be set according to vehicle design. If centralized testing is coming to your area, be very careful of any modifications made to your vehicle. Even changes to your tires sizes and gear ratios will affect this test.
Measured in emisxions, is actually excess oxygen left over from the combustion process. If this reading is very how to win chess easy, then you will also experience high CO. In boilers and other equipment, we avoid high readings as that indicates excess air which reduces heating efficiency.
This is eimssions in late model vehicles by the Oxygen Sensor circuit. The O2 sensor actually measures the Difference in O2 content hd the atmosphere and the exhaust.
When the atmosphere has more O2 than the exhaust, a small positive voltage is generated. If the mixture control system is working properly, you should see the signal fluctuate from.
This voltage correlates closely not by design, just luck with the actual CO percent Example:. This is great news as we could install a universal O2 sensor in any car and use a DMM to set the mixture.
If you wish to do this, ensure that you mount the sensor in a "hot " area of the exhaust higg it has to be heated to degrees F in order to function. This is why many cars included 86 and later Vanagons use a three wire sensor. The three wire sensor actual has a heating element built in to preheat the sensor. This enables the sensor to go on-line on a cold engine much sooner and keeps weather and driving conditions from effecting the sensor.
I find that earlier Vanagons often have problems with sensor performance as the sensor is mounted far enough down stream in the exhaust that they don't get adequately heated during emissionz weather or when the engine is idling.
This also creates havoc with emissions tests as vehicles are often tested without being thoroughly warmed up car must be driven to properly warm up all emission equipment, especially the Cat.
So what does all this mean? Well we emissipns for our test and we failed. Our van seems torun okay but it failed.
How to deal with failed emissions test and high HC
?·?A frequent cause of heartache for technicians, and car owners alike, is the failed E-test. Truth be told, just about any properly running vehicle will pass emission testing. This post will not be a laundry list of cheats. Rather, this post will be a . ?·?Hi, I have been reading these forums for a few hours now, and I'm not sure what steps to take next. I went through my smog check a couple days ago with my i (M44) with k on it in Orange County, CA. In past years, it's been an easy pass, with just the HC numbers creeping up a little. ?·?I have an old LADA Brute of a car and you can all laugh, but it starts in C and my other car doesn't. Problem is it needs to pass its test and the hydrocarbon (HC) level in the exhaust gas is too high. 3 times too high to be exact. Need ppm at idle and I am getting ppm. (Interestingly the HC level at revs drops to an acceptable 16ppm) This was measured by a local mechanic.
A high HC reading means the test found high HC hydrocarbons in your emissions. In other words, too much gas is left in the exhaust after combustion. High HC can be caused by improper combustion, where:.
The two most common causes of high HC readings are worn ignition parts and unmetered air entering the engine. A mass airflow sensor detects the amount and density of air coming into the engine. If the MAF is dirty, it can mess up the readings.
Always start by cleaning the MAF sensor. See this post for tips on how to clean a MAF sensor. This is unmetered air. But if unmetered air gets into the system, it throws off the air fuel mixture and you wind up with something like This causes a lean misfire, where the combustion process ends too soon, sending unburned gas into the exhaust.
Oh stop whining! If you want to diagnose and fix your own car, you need the right tools. If the computer adds or subtracts fuel for a short period, the results are stored under short term fuel trim. However, if the computer finds that it has to constantly add or subtract fuel, it stores the data under long term fuel trims.
A negative fuel trim value means the computer is subtracting fuel, while a positive value means the computer is adding fuel. Look for cracked or unplugged vacuum lines. Check cracks in the air duct from the air filter box to the throttle body. In many cases you can see the vacuum leak as it sucks in the liquid spray. Worn spark plugs, worn spark plug wires and a weak ignition.
Cracked spark plug Oil fouled spark plugcoil can create a weak spark, and that can prevent the combustion process from starting properly. Old worn spark plug wires introduce too much resistance and that can also result in a weak spark. One quick way to detect leaking fuel injectors is with a fuel trim reading. A negative fuel trim reading tells you the computer is trying to cut back on fuel.
The other way to test for leaking fuel injectors is to perform a leakdown test. Connect a fuel pressure gauge to the fuel rail and leave it on overnight. If the pressure drops by more than 5-psi by morning, you probably have a leaking fuel injector or a failed check valve in the fuel pump. However, a leaking check valve would also cause extended cranking first thing in the morning.
A breached head gasket can cause coolant to enter the combustion chamber. That can cause high HC readings during an emissions test. Check for a coolant leak by conducting a cooling system pressure test. It does this by storing oxygen and then releasing it into the chamber to burn off gas, oil or coolant that enters. A melted or obstructed ceramic honeycomb restricts exhaust flow causing a power reduction. This may indicate a broken Catalytic Converter ceramic honeycomb.
For more information on diagnosing a catalytic converter, see this post. They include wiring diagrams and technical service bulletins. In most cases, their diagrams are right from the factory manuals. Pricing: Eautorepair. So you have to refer to the factory legends to learn the identification symbols and then refer back to circuit diagrams to find the splice and ground locations. However, Alldatadiy. If you need to dig into your doors, dash or console, Alldatadiy.
Arcing from deteriorated spark plug wires. Find this article useful? Share it! Categories Emissions System. Tags high HC.
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