I have a 72 wagon I recently purchased. It was not tuned up very well. I did a few quick checks on timing etc. and set everything right including pulling and resealing the intake. It has vortec heads with an Edelbrock intake and Edelbrock 600 CFM electric choke carb. The timing is dead-on, the choke is working great. The car sounds like a demon and starts and runs great (it has stock exhaust manifolds with dual Flowmasters with the big block muffler - yes it is loud) until you partially mash the peddle and it bogs down. It doesn't ping, knock or... The Edelbrock carb is as shipped and I adjusted the idle mixture screws using a vacuum gauge per Edelbrock's instructions. I am at a loss and would really like to get this big 'ol behemoth moving like she should. Any thoughts, things to check? Thanks.
Frank

Check the accelarator pump.

Where is your timing set at, and is your vac adavnce hooked up?

540,
The accelerator pump works good.

Vince,
I remembered in the middle of the night that the previous owner ran the vacuum advance hose to the carb with a tee going to the canister. I have an Edelbrock on my yellow Chevelle and only have the line running to the carb. I made the adjustments on the wagon and took it for a spin. It spit once back through the carb but I have better throttle response. I previously set the timing at 8 degrees BTDC per the Haynes manual. I need to double check it. Should it be different since I have an HEI ignition? Thanks for the help.
Frank

I think you need to be at least 12* w/a smallblock, maybe somebody can correct me if I'm wrong. You need to make sure that vaccum line is full manifold vaccum - most engines seem to like that. Going to at least 12 will make a big difference.

BTW - you are setting the timing w/the vaccum advance disconnected and vaccum line plugged right?

Vince

Frank,

As I understand it, and anyone please correct me, the vacuum advance only affects the engine at cruise speed and at idel, it does nothing when you are accelerating. When you are accelerating, the vacuum drops to zero or close zero, and the vacuum is below the point where the vacuum advance will operate. I believe that normally the vacuum advance setting is up around 12 or so, where a cammed car would like it to be down around 8.5 or less of vac. On the timing, at 8 or 12 btdc, I would not expect that to cause the problem you are seeing, it may hurt performance a little. Generate a large lack of power or bog, I would not expect so. I would keep looking at the Accelerator pump, coil voltage, bad wires, bad dist cap, plugged fuel filter, real dirty air cleaner, lack of fuel or something along these lines.

Fred.

Vince,
Yes sir, plugged and then time.

SS4Speed,
I am putting in new plugs and air filter tomorrow. I previously adjusted the linkage down 1 notch on the accelerator pump but that was before the vacuum line change. It has HEI so I happen to have a cap assy I am going to swap out to see. Thanks for the help and I will let you know the outcome.

By the way, it has Flowmaster mufflers (I will double check but I believe they are the 40 series big block mufflers) and it is LOUD. What is a good flowing muffler that is quieter? I am just wanting to reduce the interior sound.
Frank

Vince,
Yes sir, plugged and then time.

SS4Speed,
I am putting in new plugs and air filter tomorrow. I previously adjusted the linkage down 1 notch on the accelerator pump but that was before the vacuum line change. It has HEI so I happen to have a cap assy I am going to swap out to see. Thanks for the help and I will let you know the outcome.

By the way, it has Flowmaster mufflers (I will double check but I believe they are the 40 series big block mufflers) and it is LOUD. What is a good flowing muffler that is quieter? I am just wanting to reduce the interior sound.
Frank
I've got the 70 series. Real quiet.