Fuel Injector Service?

[marus1608]

hey guys what exactly is fuel injector service? What exactly is done to the fuel injectors when they tell you they are going to service them? they being the shop i have the car at.

[silicon212]

Here is the way I've seen it done -

Generally, they have a small pressure vessel that is filled with a cleaner, that they plug into the 'diagnostic port' on the fuel rail (a Schrader valve, like what you'd find on a tire or AC port), temporarily disable the fuel pump, block off any fuel return lines, and pressurize the vessel and start the engine. The engine runs off of the cleaner. The engine runs until it stalls (meaning no more cleaner), and this generally cleans the injectors very well. Afterwards, they re-enable the fuel pump, remove the block on the return line (usually Vise-Grips), and remove the pressure vessel, and you're off and running!

[marus1608]

Thanks!!

[Blue Bowtie]

That method of on-car "service" has been in use for many years, and is moderately effective. There are a few commercially available machines which perform this operation. One common type is called "Motor-Vac," and there are others.

The advantage to this type of cleaner is that IF an injector is only partially clogged, and IF the inlet screens are not slugged with debris, the on-car cleaning MAY help. This type of service does nothing to insure a proper spray pattern, insure proper flow rates, or verify the propagation delays of the injectors. The only way to fully clean an injector, reverse-flush it, test the solenoid coil reactivity (propagation), and verify the proper flow is with an complete injector service. There a several places around the country which offer this service, such as Cruzin' Performance, Linder Fuel Tech, among others.

I had a vehicle "Motor-Vacced" at 18,000 miles because I suspected an injector problem. 4,000 miles later the problems still existed, and I pulled the injectors and sent them to Cruzin' Performance and found that one of the injectors was 38% off on flow, another 16% off on flow, and yet another streaming out fuel rather than atomizing it. Five out of the eight were O.K. $10 per injector and three days later, I had my set matched within 2%, new 'O' rings, new inlet screens, new rail clips, and an engine that ran better than it ever had since new.

For my money, the on-car cleaning is no more than a glorified cleaner in a bottle which you would pour into the tank, and REAL service is reverse cleaning and flow-matching - Something the on-car machines cannot possibly do. The prices have probably changed, but for less than $100 with shipping, I had a lot better experience than the Motor-Vac (which actually cost MORE).

[MT-2500]

Originally Posted by marus1608

hey guys what exactly is fuel injector service? What exactly is done to the fuel injectors when they tell you they are going to service them? they being the shop i have the car at.

The service is a can or jug of cleaner they force threw the fuel rail and injectors to help clean the injectors.
Most newer cars have more of a self cleaning type of injector that does not usually require cleaning and most fuel already has injector cleaner additive in it.
Good fuel and fuel filter is the best injector cleaner.
So most of the time it is not often really needed.
So before you even think about the service make sure it is really needed.
What car and year and engine what mileage?
Is it showing any injector problem or why are the wanting to clean them?

[twistedtech]

The motor vac is an excellent cleaning tool for getting carbon out of the entire chamber at best.A physical clean is the way to go,in fact any time I have the top end tore down enough for any given repair i just automaticly pull and clean the injectors by hand.Why not, your there.Which by the way I do not charge extra for.I would much rather hear that it runs great than have a few pennies in my pocket.