top of page

Bad Gas Mileage?          Hard start?          Rough Idle?​

         Burned up/clogged Catalytic Convertor?

You have a pretty good guess as to the cause (bad FUEL INJECTORS), but now what do you do?

The "Quick Fix" would be ANY NUMBER OF CHEMICALS -- Techron, Lucas,

Injector Sting, Gumout, Sea Foam, etc. etc.

So, you tried a bottle or 3 of these "cures in a can" and things didn't improve a bit. Or more than likely (as we know all too well here at FIS) your engine is running worse than ever, and now there is a strange noise from the gas tank area which sounds like the fuel pump going bad.

Right on both counts!

You see, too much injector cleaner can VERY EASILY dry out the synthetic rubber seals throughout your fuel system -- the NUMBER ONE cause of engine fires! And those deposits which are loosened, but not dissolved, continue through the fuel system and clog the injector filter and pintle orifice(s) -- a spray nozzle which is much smaller in diameter than a human hair!

And as an additional "bonus", these chemicals will scour clean your fuel pump bearings (yes, they have bearings). Added to the fact that most gasoline has added ETHANOL -- a form of alcohol -- and you see why shops replace LOTS of fuel pumps prematurely. Most with less than 85K miles on the vehicle.

So, what Kills Injectors in the first place? 

Three things:

1)Bad internal wiring -- (the resistance increases, or short circuits directly to ground, usually caused by vibration, heat, and in some cases, poor design).

2) Water in the Fuel -- the results of which (RUST) are deadly. Nothing in the world rusts quicker internally than an injector; they have absolutely no coatings or special metals to resist water. And, E-85, as we know too well, combines with water, and holds it beautifully in suspension. The NUMBER ONE cause of rusted injectors is E-85 in a car, or boat, which hasn't been driven for a few months. Our first clue is that we find it impossible to remove the filters -- they are locked solid to the injector with corrosion. Bye Bye injector.

3) Heat soak -- The PRIMARY reason for clogged orifices and filters, bad spray patterns, low fuel flow, and inadequate penetration. Heat soak is when you drive the car, shut it off, then the little bit of fuel left at the tip of the injector evaporates (almost, that is, leaving behind various chemical compounds), and the process repeats itself over and over for thousands and thousands of miles.

A good example of the end result of heat soak is to look at the baked-on crud on the inside of an oven which hasn't been cleaned in a while.  

The only way to avoid "heat soak" is to NOT DRIVE THE CAR! (Or not use the oven!)

Our 25+ years of experience has shown us (and has probably shown you also), that chemicals only perform adequately in FUEL SYSTEM MAINTENANCE. To keep things as they are. And maybe to help a bit in dissolving gas tank water in cold weather.

So what to do instead of chemicals?

Remove and replace the Injector of course, and basically you have 3 options:

1) New from the dealer. (Bring your wallet. Average price is $135 each, but they are the ONLY source for an exact replacement. If they can still get them, that is.)

2) New from your friendly local parts store, who does NOT usually stock BOSCH, DENSO, PICO, SIEMENS, KEIHIN, DELPHI, HOLLEY/WEBER, JECS, etc. We are recently seeing an odd substitute made by who knows who (Standard, we suspect) that has a nice new body, new top plastic, who knows what inside, and a pressed in piece of black plastic on the bottom which has three holes, supposed to be a substitute for the 4 hole or two hole Bosch, FOMOCO, etc. We will soon have pics on our new website as to the terrible inefficiency of these style universal injector substitutes. We have never found three consistent, equal sprays out of these.

3) Used from your local wrecking yard. Nothing like trading one bad injector for another!

Well now there is A FOURTH OPTION!!

As we noted in our company motto above, injectors DO NOT WEAR OUT!

Injectors are designed and manufactured to cycle (open and close) perfectly for over ONE TRILLION CYCLES. That is "Trillion" with a "T!" About 375,000 miles.

WE HAVE BEEN SUCCESSFULLY (over 90%) rebuilding injectors for

over 25 years!

Worldwide, over 5 million injectors and counting, in over 50 countries!

Here is what we do:

1) LEAK TEST your injectors at 3 different pressures.

2) Check the injector RESISTANCE at pull in AND hold in currents (a test procedure unique to our company).

3) Check the SPRAY PATTERNS of your injectors to make sure they meet manufacturer specs.

4) We FLOW TEST for correct injector VOLUME.

5) We remove and RETURN old parts -- o-rings, seals & filters.

6) Injectors are then ULTRASONICALLY CLEANED at LOW TEMPERATURE. The injectors are then ULTRASONICALLY CLEANED at HIGH TEMPERATURE (under hood engine temp, basically). This cold, then hot, temp differential loosens deposits that other cleaning processes leave behind.

7) Injectors are reassembled with top quality parts (nothing Chinese here; we prefer QUALITY!)

8) Spray pattern and volume checked and noted again.

9) Unlike ANY OTHER CLEANING SERVICE, we leak test at high AND low temperatures. Got a car which runs good cold, but gets jittery hot, or vice versa, and never sets a code, or the fuel trims don't show any terribly out of spec deviations? If you don't test hot AND cold, these defective injectors will slip past the process, and will be shown "O.k." Not at FIS!

We also do the "cross-fire" injectors! We can tell you from experience where the cross fires go bad -- it is NOT the computer, fuel pump, or oxy sensor! Everyone else runs from these -- good injectors on a cross fire, with no shorts where the wiring goes through the top of the throttle body, and these engines will purr. (Hey, we didn't say anything about horsepower!)

10) Injectors are sealed and returned. Injectors are internally lubed with gun lube to keep moisture from ruining spotless metal.

11) ADDED BONUS: BEFORE & AFTER pictures included, so you know for sure what you are getting!


Pictures of: low pressure pattern (which really shows the spray problems clearly).

Pictures of: high pressure pattern (3 bar) which shows you exactly what fuel the engine is getting.

Pictures of: operating pressure Volume -- shows you if they are equal, and we give you lbs. per hour and c.c.'s per minute values.

And finally, a picture of: how well the injector spray will penetrate the combustion chamber.

Recent addition: we give you pics of the injectors operating at 25/75 duty cycle for 60 seconds. We've caught more than a few Saturns (a car we very much like) with injectors that statically (held open) function perfectly, then are 15% off when flowing in the engine. Poor manufacturing! These Saturns have had bad injectors right out the door of the factory.


We use NO "Photoshop" or any other trickery just to get your hard earned money. Lots of injectors are just too darned difficult to have to pull, install, re-pull, then reinstall AGAIN just because the injector rebuilder had a boat payment overdue, or was in a late Friday night hurry!

Introductory offer: $20 per


     We are local to Denver, Colorado and the surrounding area. We service

repair shops and individuals who can remove their injectors and want to save

major $$$.

     All of our injector service is guaranteed for the life of your car. If, during testing, we find that one or more injectors is bad (rust, wiring) there is NO CHARGE FOR TESTING THAT INJECTOR! And you still get the pictures!

We now offer flow testing, at a nice

price of only $5 per injector.

     This includes new top O-rings (to prevent leaks when reinstalled), and more importantly, PICTURES of volume, pattern, and penetration! A killer deal!

     Think those RC or Fuel Injector Clinic injectors flow right? Let us test them and SHOW YOU while you still have a warranty, and your $5000 motor is still in one piece.

You can drop off injectors directly to:


2500 Federal Boulevard

Denver, Colorado

You can also send (mail drop only) your injectors to:


4996 Parfet Street

Wheat Ridge, Colorado 80033

Talk to us before you do. We can help in diagnosis, and

we have lots of used, rebuildable injectors in stock.

By the way, WE DO NOT CHARGE EXTRA for SIDE FEED injectors!! We have all the           adaptors, and we are the only service that can test the round top JECS side feeds found       in lots of Subarus and Nissans.

We also TEST AND REBUILD "CIS" or "K-Jet injectors."

All other injector services run from these, but we can make your older Benz, VW, Volvo, etc.      (and yes, we've even successfully done "Back to the Future" DeLoreans) purr like a            kitty.

Talk to us about our recommendations and special low pricing on these.

Sorry my friends. We do not service


    Some years back, we invested large $$ in specialized machinery to clean and test diesel injectors. Turns out, the vast majority of these injectors were killed bypoor design (internal cracks), not dirt. 

     Super high pressure, vibration harmonics from diesel combustion, diesel fuel affinity for water, etc.,and you are lucky to get 80,000 good miles (emissions and power) from these injectors.

     By the time internal parts were replaced with quality components (nothing Chinese in other words), and super precise torque values were maintained, etc., we were only about $25 away from brand new injectors. 

     Prices on NEW Diesel injectors (Duramax, and the like) have dropped dramatically. So fast, we can't keep up -- check the internet. But be wary -- DIESEL FUEL INJECTOR "reproductions" for just about any vehicle are available from the Chinese.

     Our friends at CENTRAL MOTIVE POWER, 6301 North Broadway, 303- 428-3611, can test diesel injectors for you if you want. But like us, they do not rebuild them. They are an excellent source for Diesel injector pumps, however, both testing and rebuilding. They are a VERY good source for injectors for the big stuff -- Allison, Cat and the like.



Our Phone number is: 303 456 0789

No anonymous answering service -- talk to the techs themselves!

No injector service telling youNOT to call and check on your injectors because they are too busy.

      No E-Bay injector service trying to be cheaper than the next guy by $3.00, then throwing finished injectors in a box, and there you go. We are still amazed at the number of companies who claim they rebuild, lowball a price, then take the cash and disappear when the complaints roll in.

      We are also very surprised at the junk rebuilds (GB in San Diego, and Autoline in Canada, and others) that are sold at ALL major parts stores, for about $15 more than we charge! Our personal opinion of course.

      We HIGHLY RECOMMEND, repeated, that you have us flow test these injectors if this is the route you want to go. We are seeing about a 50% reject rate (no misprint here) on these. 50%!

      Mis-packaged, mis-matched units and" leakers" (especially on Audi's and late 90's BMW's). Ouch. Which only gives the "quality" rebuilders

(us!) a shaky reputation.

      We also do MOTORCYCLES!! Our soon- to- be- appearing new web site will have a "very interesting, entertaining, and informative" commentary on early Harley side-feed fuel injectors (the Italian made, Magnetti Marelli), versus the later model American-made end-feed injectors. With loads of before, after, and "supposed to look like" pics!



                         than anybody in the business!!

bottom of page