Fuel Injection systems are a lot easier to work on and diagnose then the old carbuerators. Carbuerator rebuilding was quite expensive from the customer's point of view. The parts and labor were averaging around $500 a job.
The fuel injection cleaning process is fast and does a very good job cleaning out the carbon build up inside your engines intake system. Actually it also depended on what type of fuel system cleaning the auto shop had. Some shops had the regular 3 can cleaning system. While others had a very big and clumsy expensive machine they used.
I really liked useing the 3 can system cleaning method. It involved adding one can to the fuel tank as a fuel additive. The second can was hooked up to a high pressure source and sprayed straight into the upper intake and upper plenum area and scrubbed by hand. The third can was hooked into the cars vacum system where it was sucked down in to alot of the intake system and down around the intake and exhaust valves. There it would soak and bubble up for about 20 minutes. Then we would start the car after the 3rd can soaked and watched all the black carbon blow out the tailpipe!
After changing the fuel filter, (for an additional charge) , I could not beleive the power that was restored after this fuel system cleaning process! Just slightly pushing on the accelerator the car wanted to jump right out of the shop and take offon its own. I think it cost around $80 or $90 bucks back then but it was well worth the moneyin my opinion!