Hi, I'm new to this fantastic forum and I have a question about a '66 Mustang I just bought. It has a 289 with a 2barrel carb stock setup. When the car is in gear and your foot is on the brake the idle is very rough (almost ready to stall). A mechanic told me the hose coming from the vacuum advance was going to the wrong location. The hose currently goes to the right side of the carb. According to him it should go to a fitting on the intake manifold that is on the back of the engine. The fitting he is talking about currently has two hoses going to it, one to the transmission and the other to the brake booster. Something about this doesn't sound right so I thought I'd ask the experts (you guys). Thanks!

 

Vacuum advance goes to ported vacuum on the side of the carb not to manifold vacuum.

 

I had a rough idle after some intake work. Found the line running to my tranny modulator was off. Check it.
Walt

 

Take some pics of your current set up, then maybe we can help you get hooked up.

 

vacuum, valves too tight, low idle