The Stovebolt Site Forums The Shop Area Engine Shop Carb adjustment question

Here are the particulars. 350, 700R4, Edlebrock 1400 series(not sure of exact #). Back many years (40+) I use to be fairly good at adjusting carbs using the Tach. Turn the screws in until rpm dropped then back out until stable. Back and forth with each screw until satisfied. Here is the problem. With this carb I can screw each one all the way in without any drop in rpm. Idle is at 600 no vac lines plugged off, just hooked where they should go. What has my fading memory forgotten? Can these newer carbs even be adjusted the old way? BTW, the '48 runs ok and starts right up without problems, just running too rich.

couple of reasons that can happen --float level too high or fuel leaking around internal gaskets or the leak at power valve -use to work on all those carbs and still working on carbs -- soon carbs will get all eaten by alcohol-Beck's-

Disconnect and plug the vacuum line to the distributor. If that doesn't help, you either have a vacuum leak somewhere or an internal carb issue.
Carl

I agree with Carl

216chevy, no alcohol/ethanol anywhere near my vehicles, ever! Good possibilities for problems though.

Carl, BC52, kinda what I thought. Just hate the thought of tearing into the internals. Its been a long time since I did one.

Keep the ideas flowing folks.

Partially choke the carb with your hand. If the RPM raises that would be a good indication of a vacuum leak.

The Pontiac 400 engine in my 55 2nd truck, with Edelbrock #1405 carb, was running rich, and I suspected high fuel pressure. I installed a fuel pressure gauge and found I had 10.5 lbs pressure. Put in a fuel regulator and brought pressure down to 5 lbs. Took care of the problem.

fuel pressure regulator set at 5psi already. I'll try the above suggestions.

Guess it must be internal. Short of tearing it down I've followed all the listed suggestions. Two choices, tear it down to put a kit in it or switch to a Holley.

What is the footprint of the intake?

If squarebore, another option would be Carter 9625s or 9635s (NOT 9635sa).

If spreadbore and the e-clone is mounted on an adapter, other options would include a late 1960's or early 1970's Rochester Q-Jet for Chevy 350 OR a Carter TQ 9800s or 9810s.

The e-clones are vacuum-cast (genuine Carters were pressure-cast). The e-clones have had porosity issues. Possibly, this is your problem.

Jon.

I wonder if you have the throttle screw turned up too high, so it's running like it would if you had your foot on the gas a little. That can make the mixture screw seem to not work right.

600rpm, square bore no adaptor.m

Thanks Carbking I did not know about the porosity situation. I already have a Holley I could put on. May search for a Carter.