Did tune up on my 91 ford f150 302 5.0L V8 4x4 pick up which included s[ark plugs and wires, cap and rotor, oil change, new oil and air filters...now it is riding rougher and worse gas mileage than before? what did i do wrong?

In maintenance work a tune up would include new spark plugs, if is fitted with a distributor then replace the distributor cap and rotor. if your spark plug cables are old (more than 100,000 miles) may be good to replace them. replace air filter abd cabin filter. check the hoses that carry coolant. change oil and filter. It may be a good idea to change the coolant also to change the transmission oil.

A normal tune up is plugs/wires/cap/rotor and fuel filter. If you have a DIS (distributorless ignition system) change plugs,wires,fuel filter. You can also change oil and air filter.

distributor cap ? w/ rotor (inside) , also, a tune-up includes the following, : replace spark plugs, plug wires, both the air & fuel filters, an absolute must !!!!!! change motor oil, & oil filter. and one more maintenance issue always over looked, change the TRANSMISSION fluid & filter !!!!!! (do not over-fill ) . if everyone did all these before winter & or inspection time, they wouldn't have the problems they get.

When you want to get a tune up on your truck make sure you replace the following items. :
*spark plugs, (check your spark plug wires replacing them if needed)
*Air Filter
*Fuel filter
*PCV Valve
*Oil filter and engine oil
*Distributor cap and rotor.

Start with a complete tune-up

Plug wires can cause this.

Do spark plugs, spark plug wires, distributor cap, rotor cap, spark plug wires, fuel filter, air filter, oil & oil filter.

People often neglect these simple things which could save your motor, maintain it's efficiency plus improve gas mileage.

Here is a list. Bad timing,dirty air filter,cheap gas,old spark plugs,bad spark plug wires,bad fuel pump,bad fuel regulator,bad exhaust system meaning full of holes,dirty oil and oil filter,dirty fuel filter.

This would include your spark plugs or coils, the wires, a new distributor cap, an oil change, air filter, fuel filter, and a coolant flush. A tune up can make a car run like new again. Some don't change the fuel filter on a tune up but I have always said it is best too. They can get clogged up over time.

Throttle position sensor.

I would change the spark plugs, spark plug wires, distributor cap and rotor, fuel filter, check and change air filter if dirty, check timing, check and top off all fluids, check or change transmission fluid, check brake pads/.shoes and drums/rotors for wear and check tire pressure, check the condition of all belts and hoses and replace as needed, check condition of radiator antifreeze and top off or replace as needed.

U are correct, a 'tune up' is not an oil change, although the oil certainly can be changed at the time of a tune up (every 3k miles or twice a year if u don't drive much, and always change the oil filter too). Cars differ, mostly older to newer as to what can and should be done for a tune up. A car from the 1960's would need more parts replaced more often than a new car today (example: electronic ignitions of newer cars eliminate ignition points replacement, and generally, replacement is not as often of other parts: example, spark plugs).
So, a tune up can include spark plugs, wires, distributor cap, rotor, and I would include fuel and air filters. There are exceptions to this too, making it more complicated to generalize what to replace, as wires and spark plugs can last 100k miles now, some vehicles don't have the traditional dist. cap and rotor to replace. Check your car owners manual for an idea of what to replace and how often. If u don't have the original owners manual, check the car manufacturers web site for info. Good luck with the tune up!