Eric Hysteric wrote:
I have next question ;-) At my Carter Thermoquad i had a vacuum line from the carburetor to the air pump diverter valve. Now at my Edelbrock 1406 carburetor i have 2 vacuum ports. Timed vaccum port and manifold vacuum port. I use the timed vacuum port for the distributor and the manifold vacuum port is free. Should i connect the vacuum line from the air pump diverter valve to the manifold vacuum port at the carburetor or should i deactivate (cork) the vacuum line from the air pump diverter valve?
Sorry for not responding sooner, I've been terribly busy lately.
If I recall correctly, Edelbrock has extensive technical and support sections on their website. Based on what I've heard, they're also good at responding to emailed questions.
It's been almost two decades since I messed with (exhaust/smog) air pumps and that was on a 1980 Ford 351M. (Your air pump looks identical to the Ford one.)
The air pump injects air into the exhaust stream, usually at the exhaust manifolds. The extra air causes unspent hydrocarbons (fuel) and carbon monoxide to be converted into carbon dioxide and water. (Oxygen + heat + chemical reaction.) Hydrocarbons and carbon monoxide are major components of smog.
A non- or malfunctioning air pump system causes an increase in backfires, especially when you let off the accelerator. Before I got my Bronco straighten out, one backfire split the muffler open at the seam, sounded like a gunshot, and the police were called.
I'm fairly sure the distributor should be connected to the manifold vacuum port and the air pump diverter valve to the timed vacuum port.
But, double check with Edelbrock. (IIRC, "emission-controlled engines" is a legal rather than technical term and didn't show up until the mid-80s.)
