Poor idle

[awiedie]

If your problem is deposit related. Techron works on heat soak cycles. How many times have you run the engine up to operating & allowed it to cool to ambient Alan?

Only a couple of times and in the driveway. As Orlando and Nigel suggested, I should also get it out on the road and give it a good workout. My other problem, though, as I talked about before is that the old DG box leaks like a sieve so I have to be careful there. At least the weather is now favorable.

[Glyn Ruck]

Yes ~ you need to at least run both tanks dry out on the road. Stop/start best for quick clean up.

[Orlando St.R]

The old DG box leaks like a sieve so I have to be careful there.

The less you drive it, the more it will leak. When you use the car, the ATF is transferred from the gearbox to the torque convertor. Once the car is left for a while, the ATF drains out of the torque convertor into the gearbox, raising the level above items that are not fluid-tight, eg the speedo drive.

[awiedie]

I'm back at it again. After putting off my stalling-at-idle problem for months, I finally bit the bullet and removed the carbs, disassembled them, cleaned them very thoroughly, installed new jets, very carefully set the float levels, cleaned, cleaned, cleaned. Now, everything is back on the car, and, after flushing out the fuel lines, I turned the key on and filled the system. With the dash pots and pistons removed, you can see fuel in the jets. In the front carb, fuel is right up to the top of the jet, while in the rear carb, the fuel level is about 1/16" down in the jet. My question is, is this acceptable?

[cass3958]

I think I am right in saying that the level of fuel in the jet is level with the fuel in the float chamber. If I am right then one of your floats is set too high allowing the float chamber to over fill before the fuel is being cut off. You do not want fuel spilling out of the jet in to the body of the carb. This could cause over fueling which is fine on cold start up but might cause a problem trying to start a hot engine. It could also cause run on after switching off when hot, continually flooding one carb with fuel which goes in to the hot engine.
I personally would have my floats set a fraction lower so the fuel level in the float chamber is lower so fuel is being drawn into the carb via the jet as opposed to just lying there.
Read somewhere that the float bowl and needle valve have to be set to a point where the level of fuel is about 1/8 of an inch below the main jet.

[awiedie]

I think you're right, Cass, that the fuel level in the float chamber and jet is the same. Assuming that I have set each fork correctly at 7/16", that would mean that my front float is maybe a little heavier than the one in the rear carb and sits a little lower in the fuel and doesn't shut off the needle valve until the fuel level is higher. Could be the fork setting, but I was pretty careful. So, to move the fuel level down 1/16", I would use a 1/2" instead of a 7/16" fork setting.

[cass3958]

Sounds right. Once you have set the forks you can then check the fuel level at the needle valve and adjust again if it is still a little high. I have know some floats to have a small hole in so they take on fuel and become heavy so it might be an idea to make sure your float is not holed.

[awiedie]

I did weigh them on my postal scale before assembly and they weighed the same, about one ounce each, although that scale is probably not the most accurate one to use. That would leave fork adjustment and I'm pretty sure I wasn't out by 1/16" but it is possible. Need to recheck. First, I'm going to run the car and see how it goes.

[cass3958]

This cut out view of the Carbs was posted on another site so I thought I would bring it over to here. It shows clearly the fuel levels across the floats, needle valve main jet and the AED.

[awiedie]

Hey Cass,
Something is wrong with this cross section. I can see the point that the fuel level is the same level in all three components, but this diagram shows the fuel level in the jet WAY down in the jet. I think the relative heights of the float chamber and the carb body are drawn incorrectly because with the float height set correctly, the fuel level should be near the top of the jet. Anyway, I still haven't had a chance to fire up the old 'S' since rebuilding the carbs. More news later.