The Stovebolt Site Forums The Shop Area Engine Shop Carter W-1 having Low Idle Problem - quits running

I have a 41 Chevy 1/2 ton with a 216 and a Carter W-1. Had it rebuilt and now when I take my foot off of the gas fast like at a stop light the idle goes real low and the engine quits - The guy who rebuilt can't fix it - Some insight would be greatly appreciated,

Wayne Selway

The problem is probably in the linkage or throttle plate.
When you are tuning it, you open and close the throttle and adjust to the point that it closed. When you take your foot off the gas quickly it snaps shut, closing a little further.
Make sure throttle plate is centered in the shaft and the shaft and plate aren't dragging. Make sure the rest of the linkage is free and has enough slack.

Thanks for the reply. Are you saying the Throttle Plate should remain open just a little when your foot comes off the pedal quickly?

Wayne

"When you are tuning it, you open and close the throttle and adjust to the point that it closed. When you take your foot off the gas quickly it snaps shut, closing a little further."

That is what Jim said.

Here is a minor edit:

"When you are tuning it, you open and close the throttle and adjust to the point that is needed for the correct idle-speed. When you take your foot off the gas, throttle-flap returns/closes to the idle-speed setting."

I adjust the idle-speed to the idle RPM and then adjust the mixture to maximum vacuum at idle.
Then, re-adjust idle-speed and mixture.
Before/after adjusting the carburetor, adjust timing to maximum vacuum.

That procedure/technique might not be perfect, but it is close and it is simple and it is "fool proof".

How and where do you check Vacuum while adjusting?

Manifold vacuum fitting used for the vacuum wiper (middle driver/left side of the intake manifold, beneath the carburetor) .

Pull the throttle rod off the carb lever and check the rpm.
Is it the same as with the linkage?
Is the throttle lever on the carb tight to the shaft on to which its pressed? Does the linkage all work smooth and free from binding?
Does the long lever around the back side clear the small cover over the accelerator pump?
Is the metering rod pivot under the metal cover tight to the linkage with no extra movement up or down?

How does it run out on the road? any other problems?

A tad more idle mixture screw might help along with a little more timing. With todays fuels, you can get away with more timing, which almost always makes them run better. Try bumping the timing three or four degrees, then readjust the idle speed and mixture screw. You have to tweak each of the three to get it right, and don't be afraid to jump back and forth from rpm to mixture once you set timing up a little. No special tools needed, vacuum gauge is handy, but you can do the same by ear. Listen for smoothest idle.

The mixture screw only needs turned 1/16 at a time, when you go in ( clock wise ), you go lean which makes them stumble and rough running, turning out ( counter clock wise ) will richen it up. This is where you can get into trouble as they don't really show any sign of being to rich other then smell. 1 1/2 to 2 from a light seated position is where it should adjust to, 2 1/4 at the most. Each engine is slightly different do to altitude, barometric pressure, fuel quality, and internal condition of the engine. My engine tune changes with outside temperature, so I am always readjusting ever so slightly to keep it where I like it.

Joe

I wanted to say Thank You to everyone for their comments they were all very good for me. The problem is solved thanks to you guys.
Again THANK YOU.

Wayne

What did you do to it? don't leave us hanging.....

Joe