im stumped need help

alrite i got a 68 dart with a 318 and ive been fightin problems with a vacuum leak and just cant get it to idle right. i have changed the intake and carb. gasket ive changed all my vacuum hoses. but when i cover up the carb while its runnin the idle goes up like its suckin from somewhere, then when im not coverin it the idle goes up and down. although ive changed all the gaskets i tried spaying wd-40 around the intake where it meets the head and also around the base of the carb, but it didnt show the signs of a leak. if you guys can help me im pretty much clueless at this point

Have you cleaned the carb passages but good?

Well, it definitely sounds like a vacuum leak. Get a propane torch, turn it on (DO NOT LIGHT IT) and move the tip around any areas where there could be a leak. Don't forget the hose going to the brake booster if you have PB. If you find a leak you will hear an increase in rpm's.

Have you checked the hoses going to vacuum advance and PCV connection?

i dont have pb, ive checked the pcv hose and it seems to be in good condition as well as the vacuum advance one, and it was a brand new distributor 4 years ago before i wrecked the car and it sat in the garage. u think thats where its probably coming from though if i dont seem to be pullin air from the intake or carb?

i sprayed alot of carb cleaner on the carb passages everything but it was basically good i had changed the engine and put a new carb on it probably six months before i wrecked it and its sat in the garage since then so it has very few miles on it.

So if I'm reading this right, the carb has been sitting for 4 1/2 years without running? If that's the case I would suggest rebuilding the carb to start. Make sure to clean it thoroughly and use compressed air to blow out all of the passages. Did it run good before you parked it?

idle air passages may be cloged.

todays gas will evap in a few days leaving a bunch od grainuals/crap in the float bowls.

the ethel that add is hard on the rubber lines and needle seats also.

I would suggest opening the carb up and give a good cleaning,then reset it

ya pretty good and it even ran decent once i got it running again except my idle was real low and it tended to want to die, then i had one of my buddies mess with it to try to get the idle up but we couldnt get it to stay steady and thats when i changed everything. what i didnt understand though was yesterday when i was tinkering with it we got it running good for a little bit but then it started going up and down so its like whatevers leaking is only leaking sometimes i dont know though

also while i had it running yesterdaywhile trying to adjust it i turned down both adjustment screws completely and it continued to run? but i took them out and cleaned them, u think this is a carb problem, vacuum leak or a combination of both

Carb, pull it and tear it down clean it replace needle and seats gaskets etc. I bet if you tear it down it will smell like varnish inside, a sure sign of old deteriorated gas.

will do thanks man