projectresto83

I got my timing set at about 12 deg. and I am pulling 10-11 inches of vac at idle and it idles fine but when I give it a little gas to where the vaccum increases it sputters and pops a little out the exhaust(way to much advance). On the balancer in looks to be firing almost on the oppisite side. The mechanical advance does just fine. I know the vac canister is supposed to be adjustable but I can't get the allen head (3/32) to catch anything to adjust it.

Any ideas???????????????????

mjr46

if all you have is a stock cam 11 in hg is to low.. my 66 with 500/500 lift and 300 duration pulls that and it lopes good..I'd look for a vaccum leak somewhere...sounds like you have a lean hesitation

projectresto83

No its not the stock cam. Don't know the specs of it but The previous owner of the motor had power brake problems because of the cam. It was only getting like 7 or 8 but I set the idle mix screws today. It was doing the same problem when the plugs were black as black can be and stumbling a little when reving. I pulled the plugs after I set the idle mixture and they are starting to turn a light brown on the tops of them. I am gonna clean the plugs tomorrow and see how the look after running for a few mins. I don't have a vac leak either because I have everything other than the brake booster line plugged and when I disconnected one of them to hook up the vac gauge up the idle jumped up a little so I don't think there is a leak.

I can get an adjustable vac canister from the part store but I don't have the money right now and it is not exactly my priority since I still have to get that balancer and I am getting my flexplate I need for my other trans later this week.

mjr46

if you have off idle hesitations in a carbed car then you need to play with the accelerator pump circuit...either increase or decrease squirter size or change rate of delivery via cams if it's a holley or shorten stroke if an edelbrock

projectresto83

Its an eddy. I know what you are talking about there. But it doesn't do it when the advance isn't hooked up. It runs perfect and revs all the thru the band quick and easy. Without driving the car I have ittuned pretty nice.It just seems to be doing it when there is about 13 or more inches of vac. Will getting stiffer springs for the dizzy mess with the vac side of the advance or is that just the mechanic advance portion? I don't think it will from what I seen.

mjr46

stiffer springs will just affect the mechanical portion....at 3000to 3300 what is total advance?? should be no more than 34-36.. and I know the fac dizzy is quite liberal in that area.. I have one that registers close to 44... I like the msd set up on my 85 cause via springs I can control rate and a adjustable stop to control total advance.. = easy as pie

projectresto83

Well, as I told you before my balancer is spun so it my timing was off for awhile. But now that it is as right as its gonna get I am guessing the mechanical advance brings it out to about another 15 degrees or so by guessing the distance. It goes out nice and smooth. Do you think the the mechanical advance is going to far and then when the vac kicks in it is pulling it to much andallowing it to fire on another cylinder causing it to pop/miss and stumble? I will go out tomorrow and meassure out about another 15-25 deg on the balancer to see where the mechanical brings it out to.