Quick carb question
 

I got this neighbor with an 81 Corvette. It runs like ass and I gave it a look and the vacuum advance wasnt hooked up. I hooked up a vac pump and pulled some vacuum and it ran a lot better.

He brought it back to his mechanic and he said its not supposed to be hooked up? It's an upgraded dizzy looks like, Accel I think but there's no brain box or anything to go with it.

Is the mechanic full of ---- or do I have no idea what I'm talking about?

Re: Quick carb question
 

A vacuum advance does just that it advances the timing when it gets vacuum. There is no reason not to hook it up. usually there is a setscrew inside the tube that the vacuum lines goes onto to limit the amount of advance it can make from vacuum. if you hooked a vacuum pump up to it and it ran better then that means the car ran better with more timing. So number 1 advance the base timing. number 2 hook up the vacuum advance to the correct vacuum I always confuse the names but its the one with little vacuum at idle and a lot of vacuum under accel.

Re: Quick carb question
 

So the dizzy is upgraded but still has a vacuum advance? :S

If it's there, hook it up.

Re: Quick carb question
 

Common sense FTW!

Running locked timing generally sucks to drive, only ghetto turbo/carb guys do that.

Re: Quick carb question
 

Thanks. That's what I've been thinking. I could be wrong about the distributor being upgraded. At least the cap is upgraded and I guess it's got a coil built into the cap or some ----. Next time we're fudging with the car I'm gonna try hooking it up and resetting the timing.

Re: Quick carb question
 

Probably just an HEI cap upgrade like you said. Careful, those bitches shock you hard!

Re: Quick carb question
 

If the car runs like ass, the mechanic doesn't know what he's doing. Corvette owners like to spend money almost as much as Supra guys, even on an old affordable C3.

Re: Quick carb question
 

set base timing (4º) btdc. connect vac advance.

either that or time it 4 btdc with vac i dont remember. make sure to plug the line if its not connected.

Re: Quick carb question
 

Whatever you do, make sure you do what compl3x says. He's always rightttttttttttttttttttttttttt

Re: Quick carb question
 

you need more than 4 degrees initial timing