I got an 85 z28 305 tpi. it running like crap. gave it a tune up(plugs wires cap and rotor etc), o2, maf sensor, tps sensor, fixed a vacuum leak, checked for intake leak. I acquired a pass key and it's not pulling any codes. any ideas?

Check your fuses. My timing jumped when my ARC fuse blew.
Also get a timing light and see how ur timing is, it sounds like your timing is off.

That when I decided I was done with the computer and Im currently changing to carburated.

ok just thank about what you know already. you know its running rich...... you know you replaced all the major fuel metering sensors already.

So whats left?????

the actual injectors.... and the fuel pressure regulator.

it sounds like you are just developing a small misfire or just running rich on a couple cylinders and not more than 2 if i had too guess... in other words if the fuel presssure regulator diaphram was torn then you'd have multiple cylinders misfiring.

so my next step would be using an dvom to test your injectors ohm reading across both points.

if your still wondering how to do this you will disconnect the injector plug on any injector one at a time and test that injector using your ohm function on a dvom across both terminals, that the injector plug would plug in to.

you should get about 14 ohms on each injector give or take two. if any show infinite or majorly high resistance thats your bad injector, replace it as a minimum or better yet replace the set and be on your way g/l