For Bimmer enthusiasts, by Bimmer enthusiasts.

These fuel injectors are a massive upgrade for BMW M20, M30 and M50 motors. The four-hole design provides a better spray pattern for better fuel atomization and a wider spray pattern than the early style single pintle injectors. This not only increases power, but provides better fuel efficiency as less unburnt fuel will be sent out the exhaust.

These also provide a level of safety for your engine in modified cars. Anything from stock motors with a chip calling for 19lb injectors all the way up to built and cammed motors call for these injectors, as lower flow units can cause lean conditions which are dangerous for your motor.

Parts we stand behind.

All of our injectors are genuine, remanufactured in-house, and are covered by a lifetime, unlimited mileage warranty and exchange program. You can buy a set from us, drive 100,000 miles, and swap them for another set for just the cost of shipping! Or, if you upgrade and tune your car and need some bigger injectors, or simply want to switch to a different injector style or color, you can request an exchange for only $20 (plus any additional cost difference between sets, if applicable).

Rebuilding process

The entire testing and rebuilding process takes roughly 24 hours per set and all rebuilding is done on-site in our shop to guarantee quality. The steps are:

Step 1: Visual quality inspection, exterior cleaning, and each injector is marked with a number for testing purposes in later steps. We only service genuine OEM injectors; aftermarket (non-performance) or Chinese injectors are discarded during this step.

Step 2: Injectors are ohm tested with a multimeter, solenoids activated to test for correct opening / closing operation and tested for stuck open / stuck closed conditions.

Step 3: All serviceable parts (filters, o-rings, pintle caps, etc.) are removed and injectors are left in an injector-specific degreaser solution. There is a variety of metal types used in fuel injector construction (steel, brass, aluminum, etc.) and normal degreaser is usually harmful and corrosive to softer metals, so we use a formula and concentration level safe for the metals and polymers used in fuel injector construction.

Step 4: The injectors are washed to remove any residual degreaser solution and placed in several ultrasonic baths to break up built up contaminants. The injectors are pulsed on and off during this process to thoroughly clean the internals. The ultrasonic machine has variable temperature controls and an automatic shutoff in case the solution becomes too hot.

Step 5: Pressurized backflushing (flowing the injectors backwards) is performed to fully remove the contaminants broken down by the ultrasonic cleaner.

Step 6: The injectors are installed on the flow test machine and have a variable RPM test performed. This test "revs" the injectors as if they are on an engine from 0 to 10,000rpm, then back down to 0 again. The purpose of this test is to ensure the spray pattern is consistent throughout the rev range and does not change or falter during acceleration or deceleration. This is an important step that many shops do not test for.

Step 7: The injectors are then both statically and dynamically flow tested for +/-2% of the injector's rating. The static test simply opens the injector and measures the raw flow for a certain amount of time. The dynamic flow tests measure flow at idle, low, mid, and high RPM, respectively. These different test conditions are important as an injector that passed a static test may fail one of the dynamic tests, or vice versa. A weak solenoid, damaged pintle, or damaged internal spring may result in an injector working fine when wide open but failing a flow test when forced to open and close many times during the test. Units that fail the flow test are put through the cleaning process up to 2 more times and tested again. If they still fail after 2 more cleanings, they are discarded.

Step 7: All servicable parts that were removed in the beginning are replaced with brand new rebuild parts. Even parts that aren't 100% necessary to replace, such as pintle caps, are replaced as an extra assurance to the buyer and testament to our quality and work ethic.

Step 8 (metal body injectors with rust / damaged paint only): Both tips of the injector are masked and the injector is glass bead blasted with a special, extra-fine glass bead media. The bodies are then wiped down with isopropyl alcohol to remove any leftover media and a rust inhibitor is applied to the body (This step does not apply to metal injectors with good paint or fully plastic body injectors). Note: This means the injectors will be shipped as bare metal parts treated with an anti-rust agent before storage, and again before shipping. Any images of painted injectors in any listings are purely for display and painted sets should not be expected unless either requested or noted otherwise elsewhere in the description or options.

Compatibility Information

M20: These injectors are plug and play, however they require at least a tune to keep from running rich. 19lb injector chips for M20s can be found all online and within the modified BMW community. These are also very commonly called for in heavily built and stroked NA M20s.

M30: These injectors are a direct plug and play and provide the same flow rate as stock, so no tune is required! These will provide all the benefits of a four-hole upgrade with none of the expense of a tune or drawbacks of running too big injectors without a tune.

M50: These injectors flow slightly above stock and can be ran without a tune, however the best benefit will be found when pairing these with other mild modifications, such as a 3.5" MAF upgrade, shrouded intake, and a tune. Many chips found online are developed to run with all of these very common modifications.

M52: The same benefits as the M50. Note: These are only compatible with the M52B25, not the B28 or B28tu. Those take the black top Siemens injectors.