Fuel Injector Service
Why We Offer This Service
Most road racing cars now use electronically fuel injected engines. Proper flow through the injector is critical to maximizing the engine's power. Injectors are designed for a minimum service life of 1 billions pulses and yet many times the "down on power" problem with a race engine is caused by the fuel injectors. Here's why....
The internal tolerances inside a modern electronic fuel injector are held to 1 micron (a human hair is around 40 microns in diameter). It doesn't take a very big "foreign object" to effect an injectors performance. Dirt is an obvious contributor to deteriorated fuel injector performance. Most injectors have a built-in 30 micron filter in the inlet. If that gets plugged, flow is reduced. The truth is, though, that the vast majority of race car fuel injectors don't have plugged filters. We don't have internally rusting steel gas tanks. Unless your fuel cell foam is coming apart and you don't run a fuel filter after the fuel pump, your injector filters are probably OK. We replace the filters as part of our cleaning process, but it's probably overkill.
Much bigger problems for racing fuel injectors are long periods of storage and injector heat soak. The problem in both situations is deposits left by the fuel trapped in the injector when the engine is shut off. In the case of long storage, the fuel will turn to "varnish". Everyone's experienced this with a power tool left with fuel in the carburetor over the winter that refuses to run again in the spring. This type of deposit might be able to be cleaned with chemicals in the fuel...but maybe not.
Heat soak is a tougher problem. Heat soak is caused when the injectors and in particular the pintle head of the injectors, are exposed to very high temperatures created by the engine. Because of the location of the injector, when the engine is switched off and the injector remains closed, a small residual amount of fuel remains on the pintle end of the injector. The heat from the engine evaporates the lighter gases and the heavier particles of the fuel settle at the tip of the injector. Engine heat then bakes the heavier particles, making them a fine layer of hard, "baked on", difficult to see and difficult to remove deposits. This contamination can effect the travel and seating of the pintle, which can reduce the volume of fuel delivered, distort the spray pattern and alter fuel atomization. Only ultrasonic, solvent back-flushing of pulsing injectors has been proven to remove this baked-on contamination.
The majority of race car injectors we've tested perform adequately (not all sets are equally matched, but within specification). That being said, many of the injectors we've tested have had some kind of problem that would reduce the engine's performance -- sometimes subtly and sometimes dramatically -- and most injectors get some flow improvement with ultrasonic cleaning. The expense to clean and test a set of fuel injectors is insignificant compared to what is invested in time, money and emotion to go racing.
What We Do
Our injector cleaning/testing process is as follows:
What You Get
What It Costs