Yo M1llionb,
Is you 86 5.0 Carbureted or EFI?
I prefer Motorcraft ignition, and sensor parts via Amazon or Rockauto.
Do you need the spark plug wiring diagram?
My tune up;
Check the air filter, especially more often if the vehicle is operated under severe dusty conditions and replace or clean it as necessary.
Check the PCV valve according to the Preventive Maintenance Schedule to see if it is free and not gummed up, stuck or blocked. To check the valve, remove it from the engine and work the valve by sticking a screwdriver in the crankcase side of the valve. It should move. It is possible to clean the PCV valve by soaking it in a solvent and blowing it out with compressed air. This can restore the valve to some level of operating order. This should be used only as an emergency measure. Otherwise the valve should be replaced. It may be atop oil filler cap.
Replace Fuel filter.
Visually inspect the spark plug cables for burns, cuts, or breaks in the insulation. Check the spark plug boots and the ******* on the distributor cap and coil. Replace any damaged wiring. If no physical damage is obvious, the wires can be checked with an ohmmeter for excessive resistance.
86 5.0 Firing order: 1-5-4-2-6-3-7-8 Distributor rotation: Counterclockwise & plug wire routing