Maybe that's the way it's supposed to be. As long as the idle is steady, not sputtering or anything, that is. All you say is that it's low. I think the idle speed is supposed to be around 750 or so...not sure on that one, plus it depends on what kind of 240 you're driving. I know my 81 240 t is pretty slow in 1st and 2nd gears before you hit the higher rpm's in either gear. That's just the way it is. 3rd and 4th have good power throughout. It's possible that the timing had been advanced before and you reset it to specs, in which case your car is running just fine. The way it was meant to. If you don't like it, you could always get one of those adjustable timing gears and advance the timing a bit to gain more low-end power. I dunno.
--
1981 244 glt