I recently bought my 1989 Camaro IROC-Z equipped with a 305 TPI engine less than a year ago. It sat up for about 6-7 months before I drove it, had to get a new battery to get it to crank. It ran fine for 3 months, I was driving it to town no problems and shut it off. I returned 4 hours later and it would turnover but would not crank. I replaced the starter,spark plugs and wires, rotor button, distributor cap, pick-up coil, fuel filter, and had the ignition module and the alternator checked at advanced and they passed. I turned it over to the first mechanic and he changed the fuel pressure regulator, fuel rails and injectors, another set of spark plugs, fuel pump, remanufactured computer, and a brand new MAF sensor because the old computer showed no codes but when we put the newer one in it showed code 34 MAF sensor and we checked the wires and connectors, we got it to crank and run for a couples minutes but it ran really rough like it was starving or flooding but no smoke came out. Now it ether won't start or it takes a minute and if it does it runs rough. It's getting fuel and spark to the cylinders, plenty of air, carb cleaner doesn't help it, fuel pressure is correct, battery is charged and no codes except for 34 MAF sensor show up, OBD code reader handheld shows nothing. Obviously VATS isn't an issue, but I did remove the alarm system module and horn and left the wires, and I put in a complete sound system from cd player to speakers and subs. Basically other than that its stock. Any suggestions or related stories would be greatly appreciated.

 

Your code 34 could be set just because it is not idling correctly. Really rough idle can set code 33 and 34. I would double check the following in no specific order:

-Firing order
-Spark at all cylinders
-Fuel pressure
-Inspect plugs (What color are they?)
-Compression

When it was running really rough did it smell rich?

 

I checked two spark plugs but not all of them, fuel pressure is good, brand new spark plugs but I don't think the mechanic has checked the compression yet. I'll go one day after work and see if it smells rich and see what all he has checked this week.