CRX stumbles

I have an '88 CRX Si, when I first start it up it seems to stumble (like a misfire thru the exhaust), it runs a lot better once it's warmed up though. I changed 3 of the spark plugs but couldn't get the socket into the fourth hole. It seems a little better now. Could this be from old or bad gas ?

could be bad gas, could be many other things. sounds like either too much fuel for the ignition to handle on a cold start, or maybe other things like a bit too much oil from bad rings or valve seals. could be a tune up issue, fuel injector issue, or whatever. how did the plugs look? best way to tell if your rich or lean is reading plugs.