I just picked up a 70 pickup with a 360 and the vacuum advance on the distributor was not hooked up. I plugged it in to the carb (motorcraft 2bbl -- searching for a good used holley) and it killed the motor.

So, I plug the lines and set the timing to ~10 deg (to the right of 0 on the balancer, is this right? It seems to have marks in both directions). After I had it set, I plugged the vac. adv. back in, and it jumps up to ~35-40 degrees at idle?! (and runs like poo)

So my question is -- what the hell? Either I'm doing something wrong, or something is broken inside of the distributor. (which could be why it was unplugged in the first place -- possibly a tensioner spring?)

Sorry for the newbie question. . .

 

on most carbs, there are too vacuum lines. It sounds to me that you have it pluged into the pcv line (constent vacuum). There should be another on that should have a variable vacuum that is suppose to be plugged into the vacuum advance side of the distributor. At idle there should no vacuum on that line but once you start increasing the rpms, it starts pulling a vaccum.

chris

 

Yeah i think you plugged it to the manifold vacuum source and it caused to timing to jump sky high. Use the other source of vacuum which is ported. And it has no advance at idle.

 

Thanks, I'll try that.

 

hmm that might be my problem as well. I got the 4100 holley 2bbl. Its a decent carb, but seems to really suck gas compared to the factory one. I think you can adjuts the economy and power by using different power valves. I unfontunately have a powervalve rated at 65 which isn't very fuel effecient.

I really need to get this advance thing down, can't find any specs on how the vaccum lines are supposed to look like, anyone know where I can find pictures for holley carbs?

I hear the carter carbs are the best, lol if I only knew back when I spent the $300 on this carb.

 

The vac port is on the right side of the metering block. This is between the bowl and air horn. You might consider an adjustable vac advance.

 

yea I got manual choke with no other goodies on it, prolly some fancy add-on to get it right. But I know that my advance isn't working properly right now, can't get on the freeway at all else it goes haywire.