258 hesitation at low rpm

[epeterson]

Hello,

I have a rebuilt 258 (<200 miles) a new weber 2 bbl and an HEI ignition.

The 258 idles very rough with the timing below 12 degrees so it is now around 13-14 BTDC. There is hesitation if I step on it and low end power is sufferring a bit. Everything is fine above 2000 rpm but it is a real dog below 2000 rpm.

Is the low end power problem because of the advanced timing? And what would cause the engine to require more advance than usual?

Thanks,
Eric

 

[Collin the Hen]

Have you checked your sparkplugs after it's been up and running. I would almost bet they are black.

Try setting the timing up to 9 degrees. I've read that those Webers like a regulated fuel system. With that said, you could be running rich at low speeds which would make your idle rough.

 

[Rubiconrich]

You can run a Ford dis. cap and biiger wires to replace your AMC cap.
Ask for a Ford truck 6- cap and adt. bolts right up much better then the AMC cap.

 

[iraq_vet_x2]

A few questions....
1. Do you have the line from your vacuum advanve on your distro hooked into your carb?
2. Are you Nuttered? (if not, the list of questions gets longer)
3. Does turning on the lights kill the engine?

 

[Saddle Tramp]

My bet is it's the Weber and/or a combo with a vacuum issue, probably the jet size and adjustments. This comes from the "been there done that" file. After my experience and the lack of caring from Redline/Weber, I would take the Weber off, use it for a door stop, and find a MC 2100. You will need to change the intake manifold but in the long run it will be worth it.