Zoom Fuel system cleaner

I'll third that. My '96 is up to 232K and has never had a problem with dirty injectors.

My personal opinion is save your money and use it to buy a bottle of chevron techroline fuel injector cleaner every 5 to 10K miles. It's a proven product and only costs about $5 a bottle. I've had it improve the idle quality (often the first thing to go as injectors start building up some deposits) on several high mileage vehicles. It may take several hundred miles to start to see the improvement. It also cleans valve deposits. You can speed up the cleaning process by using two bottles at a time. That's twice the standard dose of one bottle per 15 gallons. Any more then that in a tank is not needed. A friend of mine got several research reports on the stuff from someone at Chevron and it clearly showed how well it works and at what concentrations.

I also recommend Chevron Techron. I put one bottle in a 3/4 full tank every 4-5000 miles. I buy the 4 pack at Costco for about $13. Works great on gummed up (from winter storage) outboard motors too.

At one time, fuel injector service was viable investment. When EFI first appeared on mainstream autos in North America, the gasoline at that time was ill-prepare for some of the special requirements imposed by electronic injectors. Olefinic waxes would build up on injector pintles and nozzles during the hot soak phase. These deposits would not be washed away during operation and chemical cleaners would make a marked difference in drivability.

Since then, gasoline blends have changed and are much more injector friendly.... our injector flushing apparatus sits in the corner under a thick layer of dust. I'm sure we could offer this service to our customers and make good profit.... however, we would rather earn our customers money rather than steal it....