Q: How Do Fuel Injectors Get Dirty?

asked by on November 24, 2015

How do fuel injectors get dirty?

The gasoline we buy at our local gas station may look golden-clean but, in truth, by the time it reaches the fuel injector, it has come into contact with impurities that will over time coat critical areas of the injector.

The high temperatures in the body and especially at the tip of a modern fuel injector, can promote varnishing of internal components. The injectors are amazing engineering wonders that with the advent of Direct Fuel Injection (the latest fuel injection design that places the injector directly into the combustion chamber), now routinely handle fuel pressures of up to 2000 PSI and the increased temperatures of being situated directly in the combustion chamber.

These extremely high pressures, coupled with tiny internal passages that lead to 10 to 20 micron (1 micron is the size of the period at the end of this sentence) final filter screens, mean that even minor rust, oil, or other impurities will ultimately lead to a dirty fuel injector.

Symptoms of dirty fuel injectors include a lean misfire, rough idle, hesitation and stumbling on light acceleration, a loss of power, and higher hydrocarbon (HC) and carbon monoxide (CO) emissions.

There are numerous products on the market to add to the gas tank to clean injectors as we drive and external cleaning units that force detergent-infused products through the injectors to clean minor buildup. However, once an injector gets to the point of consistently producing the symptoms listed above, the only fix will be to replace the fuel injector.

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