Need someone with car smarts. :: Ultimate MMORPG Gaming Community & Trading Zone

khrath
RealPoor Master of Posts

Joined: 11 Oct 2002
Posts: 8750

Posted: 04/19/04 - 15:40 Post subject: Need someone with car smarts.

Given time I can figure out 99% of most computer problems, the 1% I cant figure out get ghosted, but, I know d**k about cars other than basic shit. My car started like..cutting out alot, I could tell it was missing on one of the cylinders because I could unplug one of the wires and noticed no difference in the engine sound, but all the other wires made it start cutting out real bad. Anyways, Problem was solved by replacing my spark plugs...they were hella nasty, carbon overdose shit. Now like it started happening again 2 months later, same thing fixed it, only this time, just one of the plugs was bad looking. The rest looked brand new almost still, but this one had carbon on it so thick I couldnt get it off even with WD40 and a brush. So to aleviate me having to buy new plugs 6 times a year, does anyone know what might be causing some stupid shit like that? Xarp i know you'll read this because I mentioned cars in the title, please don't post anything about vanguard, and how it has self cleaning spark plugs.

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Reebo
Sir Postalot

Joined: 11 Oct 2002
Posts: 1260
Location: Downtown Miami

Posted: 04/19/04 - 16:06 Post subject:

CARBON FOULING Carbon fouling accounts for around 90% of all spark plug troubles. During combustion of the air/fuel mixture, carbon deposits can build up on the firing end of the insulator nose. As these deposits accumulate, a conductive path is formed from the centre electrode, down the insulator nose to where the insulator meets the metal shell. This build-up provides a path for the electrical current to leak through. When voltage is applied, under certain conditions, the carbon path may sink enough current so as to prevent sufficient voltage to build up at the gap, and misfire occurs. This leakage path is shown in Fig 1. NGK spark plug designs incorporate a number of features to combat carbon fouling. Some design examples are the semi-surface discharge, supplementary gap, longer insulator nose, and extended shell. Spark plug anti-fouling design features are called on by the engine manufacturer, as appropriate during the design and development stage of new engines. With standard vehicles, the recommended plug should be used and if fouling is a problem, a check on the engine conditions as outlined on page 2 should be made. The most effective property of a spark plug to prevent fouling is its ability to self clean. Self cleaning is the term used to describe the burning of carbon deposits off the insulator nose when the cylinder temperatures rise above approximately 4500C. Depending on the vehicle, self cleaning will only occur at speeds above approximately 50 km/h. During times of prolonged idling and low speed driving the engine temperature are relatively low and carbon deposits may start building up on the insulator nose. On the other hand, highway and high speed driving increase the cylinder temperature enough for the carbon deposits to be burnt away and self cleaning occurs. Note: During operation, water, oil and fuel molecules can adhere to the carbon deposits and increase the conductivity of the carbon leakage path. Fig. 1. It is important to note that spark plugs do not produce carbon deposits. If the recommended plug is being used and there is still fouling problems the following should be checked. Possible causes of carbon fouling Explanation Rich Fuel Mixture If the air/fuel mixture is rich, combustion is not complete which can result in carbon being deposited on the insulator nose. Due to this excess fuel the insulator nose is also kept at a lower temperature so existing carbon has less chance of being burnt off. Excessive Lubrication Oil Entering Into The Combustion Chamber Any oil entering the combustion chamber can build-up on the insulator nose due to high compression and heat. Clogged Air Filter If the air filter is clogged, the intake will not draw enough air for complete combustion and carbon deposits can accumulate. Weak/Deteriorated Ignition Components This can be any component in the ignition system that may have deteriorated such as the coil, leads, caps, etc. Anything that has the effect of reducing spark energy may be at fault. If spark energy is lowered, misfire can occur and carbon will build-up on the insulator. Too Cold A Spark Plug If the plug selected is too cold its operating temperature will be lower. If the temperature is not increased to allow for self-cleaning, carbon fouling is likely to occur. Over-Retarded Ignition System If the ignition system is retarded then there is less compression in the cylinder resulting in a lower operating temperature. This can result in carbon build-up because the plug may not reach its self cleaning temperature. Prolonged Low Speed Driving Or Idling The engine needs to be at a sufficient operating temperature to achieve self cleaning. During idling, engine temperatures drop below the required 450 oC for self cleaning. OTHER TYPES OF FOULING Fuel Additives This is where fuel additives are added to a normal tank of fuel to combat various engine problems such as clogged injectors etc. These additives can sometimes adhere to the firing end of the plug. Under high compression and excessive heat these additives can become conductive and result in misfire. Lead Fouling When lead contained in petrol as an octane enhancer adheres to the firing end of a spark plug it can create a leakage path as in carbon fouling. Lead fouling may not become apparent until accelerating from a middle range speed.

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Xion
RealPoor Guru

Joined: 11 Oct 2002
Posts: 2117
Location: Los Angeles, CA

Posted: 04/19/04 - 16:34 Post subject:

Sounds like you may have too rich of an air/fuel mixture, or you have some oil leaking into that cylinder.

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principessa
RealPoor Guru

Joined: 11 Oct 2002
Posts: 3149

Posted: 04/19/04 - 16:36 Post subject:

Cap, rotor, ignition wires. Ck inside the cap for cheese...inside wire caps as well. Dunno what kind of car or what brand of wires you currently have, but good wires are worth the extra few bucks... Of course, if you have a DIS....

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khrath
RealPoor Master of Posts

Joined: 11 Oct 2002
Posts: 8750

Posted: 04/19/04 - 16:39 Post subject:

my plug wires just barely made it to normal parts suppliers....they were a mopar only part for ages, had to special order them and shit....they're nice wires though, the 4 cost me like $50 I think it prolly is oil leaking into the cylinder then, cause i did notice some oil leakage lately, but not enough to make me rush off to the shop.

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Bait Masterson
RealPoor Guru

Joined: 11 Oct 2002
Posts: 3842

Posted: 04/19/04 - 16:44 Post subject:

my guess is, if its only happening on one plug, this is probably your answer

Quote:

you have some oil leaking into that cylinder.

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wellspoken
RealPoor Master of Posts

Joined: 01 Feb 2003
Posts: 7137

Posted: 04/19/04 - 16:58 Post subject:

Bait Masterson wrote:

my guess is, if its only happening on one plug, this is probably your answer

Quote:

you have some oil leaking into that cylinder.

Yep my mom had the same problem, little oil had leaked inside..

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Reebo
Sir Postalot

Joined: 11 Oct 2002
Posts: 1260
Location: Downtown Miami

Posted: 04/19/04 - 17:06 Post subject:

wellspoken wrote:

Bait Masterson wrote:

my guess is, if its only happening on one plug, this is probably your answer

Quote:

you have some oil leaking into that cylinder.

Yep my mom had the same problem, little oil had leaked inside..

Inside your mom? Shocked

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khrath
RealPoor Master of Posts

Joined: 11 Oct 2002
Posts: 8750

Posted: 04/19/04 - 17:09 Post subject:

tell her to stop whoring around in mexican bars

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Aeain
RealPoor Sensei

Joined: 22 Oct 2002
Posts: 1973

Posted: 04/19/04 - 17:52 Post subject:

Make sure a squirrel or some other rodent didn't chew through your wriring harness or anything (happened to my moms car all the cylinders didn't fire).