300sl starting problem
 

My 300sl is hard to start after it sits for a couple of days. The problem seemed to start when the intake air temp sensor fell out when I took a hard right turn and 100 yards later at a stop sign it coughed and died when I gave it some gas. That's when I saw the sensor out of place. I put it back and it ran ok for a bit.I've replaced it with a new one, left the neg. battery cable off over night and it ran great last weekend. But intermittently it just doesn't want to fire up. Once I get it running it will stumble and sometimes cut off at low rpm. If I get it above 3000rpm or so it smooths out usually. I'm at a loss here.
Any ideas please???

How old is the gas?

fresh gas with injector cleaner (lucas).