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A properly tuned engine is required for optimal engine performance. Unless the vehicle is tuned to factory specifications,
catalyst and emission related problems including catalyst efficiency codes can be triggered.

Today’s tune-up no longer simply consists of replacing plugs and checking fluids. Due to tighter engine tolerances and more sophisticated controls,
additional work may need to be performed to prevent and correct emission related codes.


How Does Carbon Build–Up Affect Engine Performance?
As the engine operates, carbon deposits may form in places such as the valves, ports, pistons, head gasket and piston
rings. This carbon can interfere with normal combustion is several ways. It can alter the engines operating temperature, compression ratio, and several other important factors involved with combustion and sensor readings.

How Can Carbon Alter the Sensor Readings?
The carbon contributes to abnormal combustion in several ways, but the most dramatic effect in a modern fuel injected
engine is the “sponge effect”. As the fuel mixture in the cylinder is compressed, the carbon has a tendency to absorb
both oxygen and fuel. Once the ignition spark fires, the flame front normally spreads through the chamber, consuming the
fuel and air, however, the carbon has a tendency to extinguish the flame front and stifle combustion.

This, combined with the fuel and air that was absorbed, results in poor efficiency. As the chamber decompresses during the exhaust portion of
the stroke, the unburned fuel and air is released, resulting in both excessive fuel and air (containing oxygen) entering the exhaust system. The O2 sensor detects the excessive oxygen and the vehicle computer (ECM, ECU, PCM) compensates for this by enriching the mixture.

This causes poor catalyst efficiency, and increased carbon formation. The situation is aggravated by the overly rich mixture, resulting in the engine’s failure to reach a sufficient temperature to remove these deposits. In addition, the excess fuel can permanently damage the catalyst or cause meltdown (on the outlet side as opposed to the inlet) and can get hot enough to melt stainless steel substrates.

Does Carbon Alter Combustion in Other Ways?
Absolutely, in addition to causing poor combustion, excessive build up can also alter the vehicle’s compression ratio. The carbon fills up spaces around the piston rings, head gasket, and spark plugs. This decreases the amount of space that is available in the combustion chamber. This increases the compression, which can cause the engine to overheat, ping
(detonate), and also causes an increase in NOX emissions.

Due to the fact that the carbon can retain oxygen from the combustion
process, it can cause another interesting effect that can cause the vehicle to either trigger a light or fail an emissions test.

A catalytic converter requires certain conditions to break down harmful emissions. It requires a slightly rich mixture and a low oxygen level in the exhaust system to break down NOX. Because the carbon causes increased NOX emissions and also causes excessive oxygen to leave the combustion chamber unconsumed, this actually impairs the catalyst’s ability
to remove the NOX from the exhaust.

Now people running alcohol injection don't have to worry about any of the above

[Daxin]

Hi,

I've been using this methanol system and I still have carbon build up. If I were to idle and have the pump running, would this be OK for the car to clean up the carbon build up? Also, I use adjustable pressure switch set at 5 psi. I also, don't boost much.

I've been using the M3 and on a 1G dsm.

thanx

[Dust]

Do you have any smaller nozzles? I would consider sticking the smallest you have in there and then manually turning the pump on. Idle and 7000 rpms have very different flow and fuel characteristics. I will be looking into a momentary switch to turn the pump full on for a little something I am thinking about.

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M1 is the smallest we carry.

[Racer704]

Methanol/Water is very good to decarbon your combustion chamber but doesnt do anything for your cat or O/2 sensor. If there is alot of carbon it will push it to the O/2 and cat . If your running a gasoline engine sooner or later your injector start to form varnish and then they dont spray a correct pattern or atomize so the fuel can then vaporise.This will cause carbon anda slight miss at idle from the fuel droplet being to large and we cant compress a liquid.

There are few products on the market that trully clean an injector and fuel system and only one that will clean the injector, O/2 and the cat as well as cleaning the carbon built up on the back of intake valves and pistons.

Most cleaners are high concentraits of Techron and other forms of petroleum distilants, they usally burn much so suity that they can make some carbon issues worse.You have many dealers that want to decarbon your engine for 100.00 plus dollars and they are really suppose to drop your cat to do it properly.

I was a GM tech for 16 until 1991 when i had a stupid moment and caught a trans and destroyed my back. The carbon cleaning agent next to water is GM Top Engine Cleaner, but it will clog up converters and GM had a bulliten about dropping cats prior to use. No one did it and still dont I am self employed and work on Pro Cut brake lathes and sell them so I am in shops all day and all the differant manufactures.

Most injectors are self cleaning but fuel is worse to day because of Katrina and the loss of the refinerys so are wounderful government allows the fuel companys to slide on the quality so they get to charge us more and do a worse job.

If you live in the US and in the midwest I would have a FFV or convert my old car to run on E-85. You wouldnt have to worry about carbon at all then and you would be at 105 octane.

If you really want to clean carbon and your fuel system along with O/2 and the cat. look into a shop that uses Terraclean, it was invinted by some very smart people at MIT by accident. What it is and how it works is a gas thats been modified to be used in a machine that hooks up like alot of other injection cleaning devices thru the shrader port. Its a 2 can kit and it uses nano technology so that its such a small droplete and then negetivly charged and it attacks carbon and varnish and dispurses it into a vapor. Now it wont break off large pices like alot of the systems being used in the dealers today.In doing so it passes thru the convertor and it also cleans the O/2 sensors and the conveter also.

Sorry I kinda ran on in this thread but you can go to there site Terraclean.net read about it and if you need a service sometime they can help you with finding a shop thats using it. I have seen slugish O/2's respond to this very well and also cars or trucks that have lost fuel milage over the years come back of course this is if everything is working mech. and elec.I also saw it unclog a convertor on a older Caprice with a old bead style. Convertors clogging up are 1 of the biggest areas for loss of fuel economy and its from carbon.

Once again to all the members i am so sorry for dragging this out. I guess my first post shouldnt have been involved..lol

I also drag race with E-85 that we blend to 118 starting with large drum of E-98 from the plant as they can send out 100% or it would be untaxed White Lightin then add a % of Sunoco NOS Supreme which is a slower burning race fuel then the rest. It works great with nitrous as we spray about 800 to 1000 hp worth of jucie.E-85 also made 75hp more over the race gas and we didnt even have the right compression as I made the switch after the piston were made so we are about 1.5 points down from where it should.

Thank you for your paitence.

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Good info.