Get a Shop Manual, and an Electrical Diagnostics manual for your year, off eBay. You can pick up a set in good condition, probably for less than 50 bucks. The Haynes and similar manuals are better than nothing... but only just, IMHO.
Examine all the things suggested, so far...
When I got my 89, I went round-and-round with 'missing', weird tach behavior, non-starting (then 'magically' it would start).
Replaced: Plug wires; coil-pack; plugs; Cam sensor; Crank sensor; Ignition Control Module, ICM (FoMoCo part), Idle Air Control (IAC) module.
Plugs/wires/coil-pack corrected miss-under-load.
Crank sensor corrected unreliable starts (finally, it failed and the car wouldn't start at all).
ICM got ride of a weird 'miss' that came irregularly, e.g., I'd be cruising down the road and it would either miss once, or twice, or if I tried to give it gas during these 'episodes', it might 'buck' for a while before it would smooth out again (subsequently running like a champ...until the next episode in anywhere from 10 to 100 miles). I originally replaced the ICM with a third-party unit. It ran good...for 500 miles, when the problem returned. My mechanic located/installed a genuine FoMoCo ICM...and no problems since (in several thousand miles).
IAC and Cam-sensor were for 'good measure'.
My car is an '89, and had been essentially undriven for up to two years before I got it (death, probate...new owner--who sold it to me).
Thus, my experience is all these things deteriorate and overlap one another somewhat as to symptoms. You can certainly save money, and do a 'surgical' diagnostic on each item. But--in my case at least--if I had just gone out and replaced all the stuff I mentioned, from the git, I'd have saved time (and perhaps money). If these items aren't 'bad' right now, and haven't been recently replaced (in the last year or two)...odds are good they will go 'bad' in the not too distant future. From my perspective, you'd be better off to start with a clean-slate...then do specific trouble-shooting in the future, on individual issues. As I said, many of the symptoms overlap. Just my experience, and opinion. There are better ways to do things, provided you have plenty of time, but wish to conserve funds.
Good luck. Now that I've sorted through all my issues, the car runs reliably with nary a miss, cough, or hiccup. There for a while, I had my doubts. But if you keep after it, eventually you get these things sorted out.
Alan