help rough idle, missing

[PNYXPS66]

I have an 88 also. First, IMHO (In My Humble Opinion) you are checking the codes wrong. Get a Haynes manual that will show you how to ground the system properly; you dont want to fry your computer. Check your ignition cap for cracks and carbon trails. The note that platinum plugs made the firing smoother suggests there may be a resistance problem in the ignition system.

A fuel distribution problem cannot be ruled out, change your fuel filter and run some hi-test fuel with some fuel system cleaner. I recommend OUTLAW fuel system cleaner. To me, it's worked the best. Also, with the engine running, pull the vacuum line off of the fuel pressure regulator. This will flood the engine with fuel and cause it to run much worse, or shut off if it is working. If it's not, there will be little or no change in the engine performance.

Another idea for fuel is to stand at the back of the car while it's running, and smell for raw fuel. You will know it because it will smell like a fuel station, and your eyes will burn. Don't do it too long, you could asphyxiate yourself.

Give it a shot.