Carb Question (Edelbrock)

[mirage86]

I've got a carbed 302. On the front of the carb, (edelbrock 1405) I've got three vac ports. The middle is PCV Vac (It's hooked up) to the right is a smaller port that I've been able to determine is "full time vac" (plugged up, what's this one) and one to the left of the PCV vac that I cannot figure out what it is but it is plugged also. The carb is mounted on a spacer that has vac ports that are plugged. I've had the car about 6 mos and I bought it more on word instead of a really inspecting it. Just wanting to get a few bugs worked out till I can get it parked and have the engine redone. It's an 86 4cyl with a 302 transplant. I believe that the prob I'm having is in the carb

Thanks

 

[battyice]

What kind of problems are you having?

The vacuum port you are calling "full time vacuum" is actually manifold vacuum. The vacuum signal is obtained from the vacuum in the intake manifold. The other vaccum port you mentioned on the left of the pcv valve is "ported vacuum".

The port vacuum signal is generated via Bernoulli's Principle in the carb's venturi. The larger the volume of air flowing through the carb, the stronger the vacuum signal at the "ported vacuum port". At idle there is very little air flowing through the carb and the vacuum signal is very small. Basically no vacuum. At wide-open throttle (WOT) and high RPM, the port vacuum signal is strongest.

Hope this helps.

 

[mirage86]

My prob is that at about 3000 RPM I lose power. The car starts sputtering. Sounds like it's flooded or starving for gas. When I shift gears or slow down, everything's fine until I get back up to the 3000 RPM range. I've read that the secondaries on the carb open when the primaries are about 65% open. I would guess that this is about the time my prob starts. I've read that a lot is dependant on air flow through the manifold, but I have no line hooked to the manifold just to the PCV.

Thanks