How do you unclog a fuel injector?

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asked Sep 23, 2023 in Repairs/Maintenance by oapster (1,480 points)
How do you unclog a fuel injector?

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answered Sep 25, 2023 by Salmorejo (41,600 points)
You can unclog a fuel injector by pouring a bottle of fuel injector cleaner in a full gas tank and then running the engine and driving the vehicle as you normally would.

If the fuel injector is really clogged then it will need to be removed and cleaned with a fuel injector cleaner system that a shop will have.

Or it can even be better and just as cheap to just replace the clogged fuel injector.

A clogged injector can feel like popping sounds from the engine, engine vibrating at idle, poor acceleration, engine cutting out, engine running rough and misfires.

Fuel injectors get clogged when debris and contaminants in the fuel get past the fuel filter and then flow through to the fuel injector which clogs the tiny ports of the fuel injector.

In some cases fuel lines corroding or rubber seals or rubber from the inside of the fuel hose or parts of the actual fuel filter coming apart can then travel to the fuel injectors and clog them.

Fuel injectors can be easy to fix if you have the proper tools such as a fuel injector puller and removal tool.

If you're pretty handy at fixing and working on vehicles it can be pretty easy to replace a fuel injector yourself but you must ensure the fuel injector is installed so that it does not leak fuel and cause a fire.

Fuel injectors take around 50,000 to 100,000 miles or sometimes longer to go bad.

Some fuel injectors may go bad within 10 to 15 years or sometimes sooner depending on the quality of fuel.

Most times it's the fuel injector getting clogged instead of the fuel injector actually failing.

The cost to fix or replace a fuel injector ranges from $300.00 to $900.00 depending on how many fuel injectors need replaced and the make and model of vehicle.

If you replace the fuel injectors yourself the cost can be between $150.00 to $400.00 or around $50.00 to $100.00 or so each.

A fuel injector injects fuel into the engines cylinders after the fuel flows from the fuel pump.

The fuel pump takes the fuel from the fuel tank and then sends it through the fuel lines and fuel filter and then up to the fuel rail where it is then sent through the fuel injectors.

The fuel injectors then spray the fuel into the engine cylinders and the spark plugs create spark from the ignition coils which then ignite the fuel which causes the engine pistons to be forced down which makes the engine move.

Bad fuel injectors do throw a code which is either P0174 or P0171 which indicates that the engine controller is detecting a lean fuel condition.

If the fuel injectors are causing a rich fuel condition or the injector is leaking or not atomizing correctly it can also throw a code.

A bad fuel injector will sound like a tapping sound or sometimes a rattling sound.

Bad fuel injectors may also leak excess fuel that can be seen or smelled in the exhaust and can be a result of a code from the oxygen sensor.

If you drive with a bad fuel injector the engine will misfire, run rough, idle rough, can be hard to start, use more fuel and could even stall.

A bad injector or bad fuel injector can in some cases ruin an engine.

If more than one fuel injector is bad and you continue driving with the bad fuel injectors then the risk of engine damage increases.

The causes of a fuel injector to go bad are contamination of fuel when debris gets past the fuel filter and then destroys the sealing surfaces or clogs the fuel injector ports.

In some cases fuel injections may also simply wear out after 200,000 or 500,000 miles or more.

Most fuel injectors will last the life of a vehicle but sometimes they fail and need replaced.

The symptoms of a fuel injector going bad include rough engine idle, engine stalling, engine sputtering, shaking, poor acceleration, engine misfires, bad fuel economy, the RPM needle that starts to dance around.

In some cases the fuel injector may simply be clogged and use of fuel injector cleaner can in most cases clear the clogged fuel injector but if the fuel injector is actually bad it will need to be replaced.

You may also have a clogged fuel line, fuel filter or bad fuel pump.

A clogged fuel injector will usually sound like a popping noise or rough idling voice.

You will usually have poor acceleration or the engine may try to cut out when you accelerate or it may also idle rough.

A normal working fuel injector normally makes a ticking sound and if you don't hear that ticking sound from the fuel injector then the fuel injector is not working.

A clogged fuel filter is caused by contaminants in the fuel or debris or fragments that can come from fuel storage tanks or fuel lines breaking down on the inside.

Contaminants such as rust in your fuel tank can also cause a clogged fuel filter.

Changing a fuel filter on a car takes on average of 10 to 30 minutes.

If your fuel filter is clogged you will need to replace the fuel filter which you can do yourself pretty easily as long as you have the proper tools.

Some fuel filters require a wrench to change out and some fuel filters require a fuel line removal tool.

The average fuel filter costs between $15.00 to $30.00 although some fuel filters may cost as much as $50.00 depending on the fuel filter and the make and model of the vehicle.

If you need your fuel pump tested a fuel pressure test will need to be performed by an auto repair shop.

The cost to test fuel pump and fuel pressure can range from $50.00 to $150.00 depending on the shop.

If your fuel pump is bad then it will need to be replaced and most fuel pumps are in the fuel tank which requires dropping the tank and that adds to cost.

Replacing an in tank fuel pump can cost between $200.00 to $500.00 depending on the vehicle you have.

Things that burns out a fuel pump are running out of fuel, electrical faults, age and wear and tear, fuel contaminants, high or low voltage.

Inline fuel pumps do have to be gravity fed so they won't burn out.

The inline fuel pump always needs some fuel in it for it to work and prevent failure of the fuel pump.

Mechanical fuel pumps put out around 1 to 4 psi while electric fuel pumps put out between 30 psi to 80 psi of fuel pressure.

Inline electric fuel pumps may only put out around 4 psi to 5 psi depending on the fuel pump.

An electric fuel pump should be no more than 2 feet from the fuel tank.

It's very important that the electric fuel pump is mounted close to the level of the bottom of the fuel tank as mounting them any higher will cause premature failure and poor performance.

The advantages of a mechanical fuel pump are no need for voltage or modules to control the fuel pump, no drop in pressure as the pump speed and fuel flow are tied to the engine speed and no overheating of fuel.

The mechanical fuel pump is mounted to the engine as well so it's easier to access to change out if you need too without having to drop the fuel tank.

Usually, a mechanical pump is preferred over an “aftermarket” electric fuel pump. They tend to be more reliable.

If the mechanical fuel pump is installed wrong then it won't work at all or it will not even supply enough fuel to the engine.

The fuel lines must be hooked up correctly for the fuel pump to work.

If the fuel pump does not work properly then the engine won't be able to start or will run rough, die out or lose power and fuel mileage.

You don't need to use gasket sealer on a mechanical fuel pump as long as you use the gasket to mount it to the engine.

However it is a good idea to add a bit of sealant to the mechanical fuel pump when mounting it to the engine to help hold the gasket in place.

A mechanical fuel pump does need to be primed which means the lines between the tank and the engine have to be filled with fuel before the mechanical fuel pump will pick up the fuel and begin pressurizing.

The mechanical fuel pumps work in the psi range of 1 to 4 psi.

Mechanical fuel pumps last on average of 100,000 miles and sometimes longer.

Although some mechanical fuel pumps may only last 30,000 miles or so before wearing out.

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