ka24de not running properly, hesistation, stall, etc

[aricanderson]

Ok I just did a head job for a friend of mine. Here's the parts that I replaced. Head gasket, intake manifold gasket, exhaust gasket, valve cover gasket, spark plugs, cylinder head, wireset, thermostat, radiator, vaccum hoses, batt, batt terminals. We changed the oil twice and changed the coolant twice. Now when we started the car it ran fine. Then a few days later the car stalls out, and sometimes starts and sometimes not. Then sometimes when it starts it seems as though when I try to keep it running with more gas it chokes out and dies. Then sometimes it will stay running. This is the wierdest problem. It may be something simple that I am forgetting. I checked and the car is getting spark and fuel, coolant and oil levels are fine and I checked for vaccum leaks and found none. What should I check next?

thanks
aric