Many people dismiss this and neglect this as much as their air intake and lubricating system.
Just a brief explanation of a fuel system before I start both diagnosis and explanation :
Electronic Fuel Injection : Fuel tank --> Electric Fuel Pump --> Fuel Filter --> Injectors --> Engine
Carb : Fuel Tank -->Fuel pump --> Mechanical Fuel Pump --> Fuel Filter --> Carb Jets --> Enginee
The EFI injectors are controlled by the ECU. Fuel pump usually pumps constant supply unless it's variable voltage and you don't see a fuel pressure regulator along the injector rails. Filters are in a metal canister as the fuel pump produces pressure constantly and it's pressure level is controlled by vacuum and boost that's in the intake manifold. The frequency of duty cycles of an injector will be controlled by the ECU, and the ECU sends data to the injectors according to : 1. how much airflow it senses from the airflow meter / 2. how much pressure it senses from the manifold absolute pressure(MAP) sensor.
The CARB engines are purely and usually mechanical. The mechanical pump in turn is rotated by a rocker arm by the camshaft and sucks fuel from the fuel tank. The carburetor, along with your right foot, will determine how much air and fuel is taken and mixed before it goes into your engine. Wont elaborate much on this.
The below are results of having a dirty fuel system :
- Rough idling or low idling - the car can barely idle or is idling at a lower than usual speed.
- Engine Knocking - Pinging or a rattling noise heard.
- Jerking, hesitation - As said, engine jerking.
- Fail puspakom - Failure of emission test.
- Problem during cold start - Car hesitates when on cold start.
- Performance loss - Loss of power.
- High fuel consumption - increase in fuel consumption, reduced gas mileage.
There are various factors for the above to happen, along with various solutions :
INJECTORS
Injectors are supposed to spray the right amount of fuel into the engine and this has to be really taken care of to avoid the above problems.
The pics describes everything. Improper spray pattern may cause insufficient and inconsistent volume of fuel being sprayed into the combustion chamber through the intake valves.
Injector LayoutThis is the inside of an injector. So complex, so many parts. Heck, this has more technology than your nokia 3310, hence, the importance of keeping it clean most of the time before the microparticles cause them to get stuck.
Ultrasonic Cleaning & Flow Testing
For worse case scenarios, injectors are taken out for ultrasonic cleaning. All gunk falls off from the sidewalls of the nozzles and so on.
The injectors are then flow tested according to various pulses, speed and duty cycle. There are also measurements of ML on each tank at the bottom of the injectors to ensure that all of them sprays a consistent volume of cc. Injectors cc/min can be calculated here.
Summary for the injectors affecting your car :
Your injectors, if they have abnormal spray pattern, air and fuel may not be able to mix properly hence causing hesitation. This can also be caused by the incorrect volume being sprayed, whereas all four cylinders will not combust at the same compressed air/fuel mixture. We all know that various mixtures produces different power. *Spark plugs color may or may not be able to tell you which injectors are defective(we will go into that later)
FUEL FILTERS
Filters, just like the one above, are well... filters. They filter whatever particles that's being sucked along with petrol from your fuel tank. I will also talk about your fuel tank later. This has to be kept clean to avoid the above problems too.
Dirty / Clogged Filters
Dirty, clogged. This restricts fuel. Maybe lets dirty fuel into the engine too. Injectors get clogged that way, imperfect combustion too due to lack of fuel for both carb and efi engines along with less purity of your fuel.
Diesel filters will need a more often replacement due to it;s dirty nature.
The solution to the above is fairly simple.... REPLACE IT. They are fairly cheap and should be replaced probably every 20,000km just to keep things clean. Again, a clean engine is a healty engine. You may have some moisture stuck in there too!
SPARK PLUGS AND FUEL TANK
PLUGS - Plugs can tell you a million stories about how is your engine running. Rich, lean, or stoich.
This is a chart of various plug readings and conditions. You can enlarge this for easier reading or juat for reference.
Okay, now THIS, shows an uneven spark plug condition. Look at number two. This cylinder is running generally leaner than the rest of the plugs. You may want to check and see if the injector is spraying properly in this particular cylinder. A white plug is a lean plug.
White vs Black plug. Lean plugs shows lean mixture. Black plug shows super rich mixture and improper combustion.If it is not tuning, something somewhere is clogged. Either injector or air filter. You may even have an incorrect fuel pressure or a weak fuel pump.
Same case.
FUEL TANK - No pictures needed for this. Fuel tank acucmulates dirt and moisture over time, I will elaborate on how to eliminate this shortly. Reason being is because every time you fill your tank at the gas station, there is bound to be moisture, or even worse, WATER, in the station's under tank. These gas stations do not pump water out of the tanks everyday, but only from time to time. So you have pretty much of a rough idea on where it goes.
SOLUTION
Now, many of you can hardly find a workshop with ultrasonic cleaning and flow testing, and a handful of you will go for off the shelf "fuel injector cleaners". I can only tell you that you want particles to melt off the sidewalls of the injectors and fuel filter, not fall off and clog the injectors. And I believe that there aren't many cleaners out there that can do the trick.
There is ONE product, also what I've been using for years and what I've been selling for years that will do the trick :
This is the brother of Lambda Primer, Lambda Tank Otto. This particular cleaner is also is endorsed by TUV, ROHS and VAG. It slowly melts deposits off and is widely used in the UK for cars that fail emission test. End users are welcomed do their own personal testing before and after with an external lambda sensor.
Recommended dosage for our local market is a 125ml bottle for cars below 2000cc and 250ml for cars that are 2000cc above. Applicable for only petrol engines. Lambda Tank Diesel also available.
Price is RM50.00/125ml and RM95.00/250ml. You can get it HERE. Pricing, availability, packages, location for COD and REVIEWS are all in the said link :). The frequency of this product is to be used after every 20,000km.
The below function of this product is taken from http://www.ruf-lambda.de/eng_version/l_produkte/tank_otto.htm
TANK OTTO
Effective cleaning of the petrol fuel system prevents problems associated with the build-up of dirt and deposits and ensures optimal combustion, substantially lower emissions and reduced environmental impact.
What it does
Removes moisture and condensation from the fuel system. Thoroughly cleans the complete fuel system and combustion chambers. Long-lasting effects ensure the prevention of obstructions due to build-up of dirt. Removes carbon deposits.
Product description
Multi-function cleaner for petrol-engine fuel systems and combustion chambers. Contains a synthetic lubricant which provides long-lasting protection against rust and corrosion as well as slowing down the build-up of dirt and deposits. Extends the life of both petrol system and engine.
Deposits removed
Rubber, gum, sulphur, and varnish contained in petrol as a result of production methods, as well as deposits which accumulate due to oxidisation of the fuel. Oxidisated and corroded metal caused by a mixture of water and alcohol in the system.
Suitable engine types
All types of petrol engines which run on leaded petrol, unleaded petrol, and liquid petroleum gas (LPG), with or without catalytic converter. Recommended for catalised and turbo-charged engines.
Areas treated
Petrol tank
Fuel pump
Fuel pipes
Injection system
Combustion chamber
Carburettor
Fuel distributor
Inlet and exhaust valves
Oxygen sensor
E.G.R. valve
Catalytic converter
Areas the product treats:
Removes deposits, cleans and lubricates the pre-combustion area as follows:
- Fuel tank
- Fuel lines
- Fuel pump
- Fuel injectors
- Intake ports
- And/or carburettors
- Valve stems
- Valve seats
- Combustion chambers
- Heads of intake valves
Post combustion areas:
- Seats egr valves
- Catalytic converters
- Stems & heads of exhaust valves
- Oxygen sensors
Summary Overall :
Once the entire fuel system is clean, there is no need to be worried for upcoming problems. Once the problem occurs, your fuel system can immediately be ruled out :)
Cheers
Elton
Great post about the preventive measures of fuel for the car!
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