Everything these days is "fuel injection" and computer controlled. But don't let that scare you.
If you have the right tools for the job, you can do quite a bit yourself.
In general for all vehicles...
The main tools for the job are a factory service manual set (order from dealer), a multimeter, a fuel pressure testing gauge, and a code reader.
Sometimes factory service manual sets are sold as separate books. You need to buy the complete set. There could be a basic factory service manual. Then an engine "fuel and emissions" book - this is misleading. Actually it is everything you need to troubleshoot engine problems. Not just emissions. And then an electrical wiring diagrams manual.
Some newer vehicle service manuals sets might be 4 volumes and a total of 2000 pages and everything is all mixed in together.
I frequently need ALL the books!
The factory service manual will tell you specifically what and where to test with the multimeter. Then depending on the results, it will tell you where to go from there. These books usually have sections on how to use a multimeter as well.
The computers in vehicles can figure out problems and alert you with the "check engine" light. Then you can read the code with an OBD II code reader. Then look for the code in the factory service manual, then it will tell you what to test. Usually with a multimeter.
And the factory service manuals will give you a list of things to service / check at various mileage intervals.
Newer vehicles have more than just an engine computer. There may be a anti-lock brakes computer, and air conditioning computer, an air bag computer, and a computer to roll down the windows!
But many "code readers" sold in auto parts stores will only read the diagnostic codes from the engine computer. If you are having problems with a "new fangled" electronic air conditioning system or the anti-lock brake system, these code readers would be useless!
There are newer "consumer" code readers on the market which will read more codes than just the engine computer codes. You may need to buy this off the internet to get the latest and greatest. Check around and ask on a Ford specific automotive forum.
The mechanics use code readers that cost $3000.00 and these can read ANY code from any computer in the vehicle. But that is not an option so far as I am concerned.
Here is a search of google.com for the words...
Ford OBD II code reader brakes transmission cart
So far as the engine goes, there are electronic sensors which give input to the engine computer. Then the engine computer adjusts the fuel, air, and timing so the engine runs just right.
For example there is a sensor which checks the temperature of the coolant circulating in the engine/radiator. When it is cold, it will adjust the engine one way. Warm another way. And hot another way.
If that sensor is faulty and telling the computer the engine is cold when it is hot, the engine will not run right. And the way to check this sensor to see if it is working ok is to use a thermometer to measure the temperature, remove the electrical connector to the sensor, then measure the "resistance" of the sensor with the multimeter set to "ohms".
The factory service manual will give you complete instructions on how to test this.
And that is all there is to it. Just test different things as directed by the instructions. Then you only replace the part which needs replacement.
Some people don't read and will just start replacing parts. This is called "throwing parts at the problem". They spend a fortune doing this, then the problem turns out to be a loose ground wire somewhere and they didn't need to buy any parts!