Frequently Asked Questions about Fuel Injectors

Fuel Injector FAQ

Find answers to common questions about fuel injectors here. If you have a question about fuel injectors that is not covered on this page, please contact us or give us a call at (562) 867-4999 and we'd be happy to provide the answer.


Do my fuel injectors come with new O-rings?

Yes, all of our fuel injectors will include the proper, brand-new Viton O-rings and/or seals for installation. We also include a tube of synthetic lube for proper installation with all new sets of injectors.

Can I install higher flowing fuel injectors in my stock or nearly-stock engine to add horsepower?

The answer is yes. But, only if you do it right.
If you install a high-flow fuel injector even a set that only flows 10-15% over stock, you risk over-fueling the engine. The result is fouled spark plugs, erratic idle, power surging and even permanent damage to the catalytic converter and your engine. Installing higher flowing fuel injectors alone will not increase horsepower.

On the other-hand if you are willing to spend the extra money to do it right, keep reading.
Fiveomotorsport offers Stage 1 fuel injector upgrades for over 300 different engine applications. If you don't see what you are looking for on our website, call or email us. Our technicians will help you make the correct choice for your application based on your specific engine parameters. The basic steps include the following:

  • Buy the Stage 1 fuel injector set listed for your stock engine.
  • Take the fuel injectors uninstalled with your vehicle to a professional tuner.
  • The pro tuner can install the new fuel injectors and retune and reset the timing on your engine using the stock reprogrammed controller.
  • This will increase horsepower and torque.

Example power increase: 120ft/lbs torque and 80 horsepower on a 6 cylinder 3.5 liter Eco-boost Ford F150. That’s money wisely spent for newly added horsepower and torque! Compare this to money spent on exhaust and headers just to add 30 horsepower!

What is an injector's static flow-rate and dynamic flow-rate?

In general, dynamic means energetic, capable of action and/or change, or forceful, while static means stationary or fixed. Static flow-rate is the injector flowing in a wide open position and referred to as 100% duty cycle.

When a fuel injector is tested at a specific pressure and the injector's internal mechanism is held open allowing fuel (or in this case testing fluid) to flow at a constant rate, we then measure the amount of testing fluid and this is the static flow-rate. Flow rates are most commonly measured metrically in cubic centimeters per min shown as cc/min, and in the US as pounds per hour shown as lbs/hr. The most common pressure applied to a fuel system or an injector test-bench when conducting these tests is 3 BAR or 43.5 psi.

Dynamic flow rates are measured when the fuel injector is in action--opening and closing at specified intervals under pressure. On the injector test bench parameters such as engine RPM, voltage and injector open and close rate measured in milliseconds or ms can be simulated. These dynamic test results give us a more complete and accurate example of how a specific fuel injector will function in a real-life situation when operating in the engine. All of our custom, flow matched fuel injector sets are tested both statically and dynamically for true results that will improve your performance.

What type of fuel injectors are right for my application?

Learn more about your fuel injector options. By clicking this link you can learn about the different types of fuel injectors we offer to our customers.

How do I know if my current injectors are low impedance or high impedance?

By measuring the resistance across the two electrical terminals of the injector with a multimeter, you can determine the impedance. If the resistance is between 1.5 and 4.0 Ohms, you have low impedance injectors (Low Z). If the resistance is between 8 and 16 Ohms, you have high impedance injectors (High Z).

Can you upgrade fuel injectors?

Yes, a fuel injector upgrade is a great option to help add miles-per-gallon or restore lost power and torque in older or high-mileage engines. The first thing to know is "upgrading" does not mean changing the injector flow-rate. Upgrading means replacing old, worn, OEM fuel injectors with a new set of fuel injectors. This upgrade alone can improve the overall performance of an older engine.

Upgrading to newer technology fuel injectors is the best way to go. If your engine has EV-1 fuel injectors there may be a new-generation EV-6 or EV-14 injector upgrade available that has been cross-referenced to match the specifications of your OEM injectors. A new-generation fuel injector upgrade may seem costly, but this upgrade can easily pay for itself in no time with fuel cost savings.

What will bigger fuel injectors do?

Installing bigger (higher flow) fuel injectors to your stock engine is not advised unless other changes to your fuel system and/or re-mapping of the ECU is also done. The engine control unit (ECU), fuel and O2 sensors, and the fuel pressure regulator are all working together to maintain the proper air-fuel ratio (AFR) for optimum engine performance. Changing one part of this system, for instance installing high-flow fuel injectors, without changing or adjusting the others can cause misfires, erratic engine rpm, and lowered fuel economy, and could result in possible damage to your engine.

Installing higher flow fuel injectors to your modified engine can be done. Please contact us or check out our flow-rate calculator for help deciding which fuel injector upgrade is right for your engine.

How are fuel injectors rated?

Fuel injectors on our website are rated using the US manufacturing standard which measures the static flow or open flow rate in pounds of fuel per hour at a given fuel pressure (lbs/hr at 43.5 psi). Other import application might use the metric equivalent of milliliters or cubic centimeters per minute (cc/min @ 3 Bar or 300 kPa) or grams per second (g/sec @ 3 Bar or 300 kPa). An example of a modern port fuel injector can be rated at 36 lbs/hr., meaning this fuel injector, with 43.5 psi fuel pressure will produce 36 pounds of fuel in one hour.

What does fuel injection service include?

Electronic Fuel Injector Reconditioning and Restoration Service

  • Restore injectors back to like-new specifications
  • Regain power and performance
  • New O-rings included with service
  • Injector internal coil must be in working condition
  • Price shown is per injector running gasoline and/or oxygenated fuels
  • CNG (compressed natural gas) injector restoration costs a bit more (see drop-down menu)

This service includes the following:

  • Extensive ultrasonic cleaning using state-of-the-art equipment
  • High pressure back-flowing
  • Flow-testing and data reporting
  • Replacement of all rubber parts