Picked up a 95 for $200 last week. Was told it had been sitting roughly 3 years and needed a fuel pump but upon further inspection and after scratching my head, it was the computer. I replaced the pcm and it ran, but rough. I replaced the plugs, and pumped 15 gallons of dead fuel out, put about half a tank of 93 in it, and it ran great but had a high idle and a hesitation once you got in the throttle, but it progressively got better..

until today, I got off work, come home, crunk it and it didn’t want to hardly run at all. Running super rich, sputtering, shaking, and so on. I unplugged the tps and it ran good. I changed that, reset the computer, and no difference. I pulled the plugs (that I just put in) and they are basically fouled. I will add that the cap, rotor, and wires was changed by the previous owner and are brand new. Does anyone have any suggestions?

edit: it’s also throwing a misfire code as well as a lean mixture code

 

Fuel filter clogged? Probably needs some kind of good flush through the whole fuel system. May not be getting good fuel to the engine.
Also O2 sensors may be garbage after sitting for so long so your computer doesnt know how much fuel to give, or not give. Try checking all the sensors associated with air intake system. Computer needs those readings as well to give proper fuel amount.

 

changed fuel filter and O2 sensor. No change. Also changed map, tps, and iac and that didn’t make a difference either

edit- idk if this could be related to the misfire problem but the first time I crank it on the new computer and it ran good, all I had to do was turn the switch, but now I’m order to start it I have to jump the fuel pump at the fuel pump relay.

 

Have you allowed it to relearn idle? May not be the problem but can't hurt. Also one time my TVC came loose and caused a really rough idle, luckily I had noticed the throttle become extremely responsive so that was the first thing I checked.
"Clear the ECM memory, and let the vehicle idle for 2 minutes in park with A/C off, 2 minutes in park with A/C on, 2 minutes in gear with A/C on, 2 minutes in gear with A/C off."

 

I’ll try that when I get a chance, idk if this could be related to the misfire problem but the first time I crank it on the new computer and it ran good, all I had to do was turn the switch, but now In order to start it I have to jump the fuel pump at the fuel pump relay so I have fuel at the rails.