📖 What It Does
Atomizes fuel into a fine mist for clean combustion. The ECU controls injector "pulse width" (open time) down to fractions of a millisecond to match air mass, throttle position, and a dozen other variables.
⚙ How It Works
When the ECU energizes the injector's coil, a tiny plunger lifts off its seat, allowing pressurized fuel to spray through precision-machined holes in the tip. Port injectors fire into the intake runner. Direct injectors fire straight into the cylinder under much higher pressure (500–3,000 psi).
⚠ Symptoms When It Fails
Symptoms include misfires, rough idle, hard starts, P0201-P0208 codes, fuel odor, poor fuel economy, and black smoke from rich-running cylinders. Carbon buildup or internal failure are the usual causes. See full symptom guide.
💰 Replacement Cost
Replacement: $250–$1,500. Port injectors are $50–$150 each. Direct injectors are $200–$500 each. Most shops recommend replacing a set, not just one. See injector cost.
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❓ Frequently Asked Questions
Can I clean clogged injectors instead of replacing them?
Often yes. A professional ultrasonic clean or a quality in-tank cleaner can restore many injectors.
How long do fuel injectors last?
Port injectors often last 150,000+ miles. Direct injectors fail more often, sometimes by 80,000–100,000 miles.
Does fuel system cleaner work?
For port-injected engines, top-tier gas additives clean injectors well. Direct injectors need walnut blasting on intake valves more than injector cleaning.
Will a stuck-open injector flood the engine?
Yes. You may not be able to start the car at all.
Why are some injectors so expensive?
Direct injection injectors are precision parts that handle 2,000+ psi. Tolerances are extreme.
Should I replace injectors as a set?
Yes if mileage is high or one has failed - the others are usually close behind.