GevPwr’s view on servicing your fuel injectors

Almost no manufacturer recommends fuel injector cleaning maintenance under normal operating conditions. From a manufacturer’s viewpoint: take care of your car and drive in none-race conditions than you’ll be fine.

We have also seen publications that indicate it should be maintained anywhere between 15,000 to 60,000 miles.  As you can see the mileage variance is so high that you really can’t go by driven mileage or by manufacturer’s recommendation unless you baby your car when it comes to driving and maintenance.


  1. If you notice a downgrade in fuel economy over a few tanks of gas, this may be an indication that your fuel injectors may need servicing or at least to be tested.
  2. You are experiencing rough idle, stalling, poor acceleration.  These may all be signs that you need to at least get your injectors tested and serviced.
  3. Your car has been sitting for a long time without running the engine.  There is a good chance injectors are not going to work evenly and flow the same amount of fuel.
  4. Your car needs tuning, it is a good idea to spend a little to make sure injectors are fine before starting the tuning process.
  5. If you are running on E85 it attracts water which helps to accelerate the corrosive effect on fuel systems.  Manufacturers place coating on the injectors to counter this effect but some put fewer layers of coating then others and corrosion occur. If you notice any of the conditions 1, 2 or 3 then it’s time to get the injectors at least tested.
  6. There are times where you have two same model/year/engine cars with same modifications and tune yet one car is performing much better than the other.  In this case, fuel injectors on the slower car should be checked to make sure it is not the reason.
  7. For your peace-of-mind, before a race, it is a good idea to check your car’s injectors before subjecting the injectors into a high flow condition where every drop of fuel matters.
  8. It’s better to spend a little money now to make sure injectors are spraying evenly than to later have them cause you more costly expenses.

Testing Only – $15 Per Injector

Testing and Cleaning – $30 Per Injector

Ultrasonic Exterior Body Cleaning Ultrasonic Exterior Body Cleaning
Electrical Circuitry Testing Electrical Circuitry Testing
Leak Testing Leak Testing
Spray Pattern Inspection
Spray Pattern Inspection
Flow Rate Recording (idol, medium, static) Flow Rate Recording and Comparing (idol, medium, static)
 Does NOT Include Fuel Path Cleaning Ultrasonic Fuel Path Cleaning
 No Parts are Replaced or Serviced Pressurized Back Flush Cleaning
Replacing all O-Rings
  Replace Filters (if applicable to injector style)
  Replace Pintle Caps (if applicable to injector style)
Injector Inspection Report Injector Inspection Report Before and After Cleaning
Recommendations Recommendations


Injector Shipping Instructions

Print customer information sheets, fill out and enclose it with your injectors.

It’s best not to remove any parts from the injector as we will return all parts back to you.  In case you are seeking only GevPwr testing service than all parts have to be on the injector for us to run the tests.

Please only send the injector and not the fuel rails or any hold-down brackets, clips, etc.

If you don’t plan on using the injector right away please don’t remove them from the airtight bag we shipped them in.  As a precaution we automatically lubricate all injectors before packaging to extend the life when not in use.

Packing and shipping

Its important that you let gas drain out of your injectors than wrap your injectors individually in a paper towel and put them in a plastic  zip-lock bag.

We recommended that your injectors are shipped in a box and not in a padded envelope to keep them from getting damaged.
For your safety please purchase shipping insurance and get delivery conformation with tracking number so you know when we receive your injectors.

Return shipping

We return ship via priority mail and charge a $15.00 plus insurance.

We do not ship back uninsured or grossly under-insured without you take full responsibility if injectors are lost or damaged during shipping. On the form please indicate how much return shipping insurance you like to purchase as GevPwr takes no responsibility for loss or damage during shipping.  The cost is $1.75 for each $100 of insurance you purchase.

We do not ship internationally, only to US addresses on continental United States except Alaska.

Why choose GevPwr for my injector servicing or any other service?

GevPwr goes beyond just understanding injectors and how they function. We understand your high-performance car from front bumper to your car’s tail pipe yet we don’t charge extra for using this knowledge to make your car perform it’s best. Our prices are reasonable for the service we provide and because of our knowledge we can quickly diagnose and repair almost any part of your car like engine, transmission, differential, fuel system, break system, exhaust or intake system, supercharger or turbocharger, air conditioning system basically there is nothing on late model GM performance cars we are not an expert in.
Our in-house experts can even put together a new car harness while many other shops avoid touching the electronics. This alone uniquely qualifies us to repair/replace your electromechanical fuel injectors.
We test injectors using same equipment that a global high volume injector re-manufacturer uses.

Does GevPwr “rebuild” fuel injectors?

Nobody really rebuilds gasoline injectors, since they are a sealed unit and can’t be completely disassembled. We clean the outside, inspect, test, ultrasonically clean inside and replace any serviceable parts, (such as filters, O-rings, & pintle caps). Some call this process rebuilding.

What is the normal turn-around time?

In most cases, we turn-around and ship your injectors in 1-2 business days of receiving them.

What is Flow Matching?

We want all the injectors to flow same amount of fuel or as close as possible otherwise the engine computer to a degree will make changes to injector operations to compensate for differences between injectors (note: most car computers can’t make modification to one cylinder so they make adjustments to all). We clean until injectors are responsive enough to flow almost same amount of fuel or at least the slow flow compared to the high flow is no more than 1.5%. Anything more the computer compensation will eventually not work well plus you will be losing fuel economy, responsiveness and power, not to mention polluting the air. Think of this for a second, if you have one bad or low flowing injector than the engine computer will force more fuel to all injectors to bring this one injector to flow the minimum amount needed. You end up dumping extra fuel and lose power and economy.  Injects rarely fail yet they do get dirty based on many conditions and cleaning them bring the injector back to normal functioning state.

What kind of injectors does GevPwr service?

First the type of injectors we don’t service:
– Diesel, as diesel requires different testing equipment.
– GM Truck Vortec CPI injector “spider” assemblies. These have the plastic hoses and poppet valves.
– GDI injectors, (Gasoline Direct Injection) these spray fuel directly into the cylinder and are normally used on a few high-end cars in the last 2 years. Our equipment tests GDI but we don’t stock parts for them.
– CIS, injectors. They don’t clean well due to design, and the internal filters are not replaceable.
We can service the following type of gasoline injectors:
– Top feed
– Side feed
– Throttle body
– Motorcycle, ATV, Snowmobiles, & Marine

What are the symptoms of possible injector problems?

Many shops either ignore injectors as possibly being the problem or just change one injector which may not solve the problem because it most likely flows different than the other injectors. Here is a list of possible issues you may face because of one or more clogged injectors:
– “Check Engine” light or cylinder misfire code
– Poor idle
– Light throttle surging or bucking
– Denotation (knocking or pinging), causing possible engine damage
– Low speed hesitation and surging issues
– Emission problems
– Loss of performance
– Increased fuel consumption
Leaky injectors can cause:
– Hard starting, especially when hot
– Poor idle
– Emission problems
– Increased fuel consumption
– Exhaust odor
External Injector leak:
– A fire hazard and should be discarded.

Why do injectors need cleaning?

Modern fuels are a complex blend of hydrocarbons and additives, many of which evaporate at different temperatures. Each time a hot engine is shutdown (heat soak), a small amount of gasoline is left on the tip of the each injector. Since the engine temperature is now above 200 degrees F, the more volatile compounds in the fuel evaporates and the less volatile elements dry on the injector tip and form solids. As time goes on, these accumulations grow and start affecting the injector spray pattern and fuel distribution.
Both Turbo and Supercharged engines are very tough on injectors due to the higher intake temperatures and turbo oil getting past the seals and depositing on the injector tips.
Older engines with worn rings and valve guides also contribute to the build-up. This blow-by gets introduced into the intake by the PCV system.  Consider getting a catch can.  For Cadillac CTS-V GevPwr has a custom catch can for it.
Failure to change the fuel filter and allowing moisture in the gas tank both have detrimental effects on the injectors. Rust can deposit itself below the injector filter and can cause serious problems.
E85 fuel attracts water and its best to keep the gas tank as full as possible that way there will be less air in the tank for E85 to attract water molecules from the air.

Do we modify injectors to increase the flow?

Very few injectors can be modified to increase the flow and still work correctly. Usually the spray patterns will be poor and their flow rates will be very mismatched after modification.

Can stuck injectors that have sat for years be serviced?

Injectors that are stuck closed due to non-use for long periods can usually be serviced. In some cases, corrosion has damaged them to a point where they cannot be saved.

  1. Exteriors are ultrasonically cleaned, visually inspected, and numbered.
  2. Injectors are tested and recorded for resistance (ohm) by our machine. If an injector fails this test no further attempt will be made to clean that injector.
  3. Electronically tested for inductance, shorts, and current draw.
  4. Leak testing is done.
  5. Spray pattern and flow rate is tests and recorded..
  6. Filter baskets and pintle caps are removed where applicable.
  7. Our special ultrasonic cleaning process is performed. During this process, the cleaning solution is heated while the injectors are pulsed at various rates as the ultrasonic machine automatically applies different ultrasonic wave length to loosen any residue inside the injector.
  8. Individually back-flush is performed with testing liquid to remove ultrasonically loosened particles left inside the injector plus to wash away the cleaning fluid. Our machine does not mix cleaning solution with testing solution as our testing solution is in a seal-tight chamber in the testing machine.
  9. Injectors are retested for: leaks, spray pattern and flow, and the results are recorded.
  10. New filter baskets, O-rings, and pintle caps are installed if and where applicable.
  11. The injectors are lubricated and placed in sealed airtight plastic bags.
  12. A comprehensive test report is prepared and returned with the injectors.